support for "r" prefixed variables in ARM inline assembly #4

nickdesaulniers · 2018-03-22T16:50:02Z

ARMv8 added support for register prefixes "w" (eg w0, w1) for lower 32b and "x" (eg x0, x1) for full 64b of the same register. GCC also supports the ARMv7 "r" prefixes, but clang complains for ARMv8 that this is ambiguous.

LLVM Bug: https://llvm.org/pr36862
Chromium Bug: https://bugs.chromium.org/p/chromium/issues/detail?id=824526
Example Android workaround: https://android-review.googlesource.com/c/kernel/common/+/645181

nickdesaulniers · 2018-03-22T22:17:19Z

temp patch sent upstream to linux by @mkaehlcke: https://patchwork.kernel.org/patch/10302339/

nickdesaulniers · 2018-03-26T16:27:21Z

patch to LLVM started: https://reviews.llvm.org/D44815

mkaehlcke · 2018-04-03T22:33:39Z

https://reviews.llvm.org/D44815 has landed.

As Wen Xu reported in below link: https://bugzilla.kernel.org/show_bug.cgi?id=200183 - Overview Divide zero in reset_curseg() when mounting a crafted f2fs image - Reproduce - Kernel message [ 588.281510] divide error: 0000 [#1] SMP KASAN PTI [ 588.282701] CPU: 0 PID: 1293 Comm: mount Not tainted 4.18.0-rc1+ #4 [ 588.284000] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 [ 588.286178] RIP: 0010:reset_curseg+0x94/0x1a0 [ 588.298166] RSP: 0018:ffff8801e88d7940 EFLAGS: 00010246 [ 588.299360] RAX: 0000000000000014 RBX: ffff8801e1d46d00 RCX: ffffffffb88bf60b [ 588.300809] RDX: 0000000000000000 RSI: dffffc0000000000 RDI: ffff8801e1d46d64 [ 588.305272] R13: 0000000000000000 R14: 0000000000000014 R15: 0000000000000000 [ 588.306822] FS: 00007fad85008840(0000) GS:ffff8801f6e00000(0000) knlGS:0000000000000000 [ 588.308456] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 588.309623] CR2: 0000000001705078 CR3: 00000001f30f8000 CR4: 00000000000006f0 [ 588.311085] Call Trace: [ 588.311637] f2fs_build_segment_manager+0x103f/0x3410 [ 588.316136] ? f2fs_commit_super+0x1b0/0x1b0 [ 588.317031] ? set_blocksize+0x90/0x140 [ 588.319473] f2fs_mount+0x15/0x20 [ 588.320166] mount_fs+0x60/0x1a0 [ 588.320847] ? alloc_vfsmnt+0x309/0x360 [ 588.321647] vfs_kern_mount+0x6b/0x1a0 [ 588.322432] do_mount+0x34a/0x18c0 [ 588.323175] ? strndup_user+0x46/0x70 [ 588.323937] ? copy_mount_string+0x20/0x20 [ 588.324793] ? memcg_kmem_put_cache+0x1b/0xa0 [ 588.325702] ? kasan_check_write+0x14/0x20 [ 588.326562] ? _copy_from_user+0x6a/0x90 [ 588.327375] ? memdup_user+0x42/0x60 [ 588.328118] ksys_mount+0x83/0xd0 [ 588.328808] __x64_sys_mount+0x67/0x80 [ 588.329607] do_syscall_64+0x78/0x170 [ 588.330400] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 588.331461] RIP: 0033:0x7fad848e8b9a [ 588.336022] RSP: 002b:00007ffd7c5b6be8 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5 [ 588.337547] RAX: ffffffffffffffda RBX: 00000000016f8030 RCX: 00007fad848e8b9a [ 588.338999] RDX: 00000000016f8210 RSI: 00000000016f9f30 RDI: 0000000001700ec0 [ 588.340442] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000013 [ 588.341887] R10: 00000000c0ed0000 R11: 0000000000000206 R12: 0000000001700ec0 [ 588.343341] R13: 00000000016f8210 R14: 0000000000000000 R15: 0000000000000003 [ 588.354891] ---[ end trace 4ce02f25ff7d3df5 ]--- [ 588.355862] RIP: 0010:reset_curseg+0x94/0x1a0 [ 588.360742] RSP: 0018:ffff8801e88d7940 EFLAGS: 00010246 [ 588.361812] RAX: 0000000000000014 RBX: ffff8801e1d46d00 RCX: ffffffffb88bf60b [ 588.363485] RDX: 0000000000000000 RSI: dffffc0000000000 RDI: ffff8801e1d46d64 [ 588.365213] RBP: ffff8801e88d7968 R08: ffffed003c32266f R09: ffffed003c32266f [ 588.366661] R10: 0000000000000001 R11: ffffed003c32266e R12: ffff8801f0337700 [ 588.368110] R13: 0000000000000000 R14: 0000000000000014 R15: 0000000000000000 [ 588.370057] FS: 00007fad85008840(0000) GS:ffff8801f6e00000(0000) knlGS:0000000000000000 [ 588.372099] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 588.373291] CR2: 0000000001705078 CR3: 00000001f30f8000 CR4: 00000000000006f0 - Location https://elixir.bootlin.com/linux/latest/source/fs/f2fs/segment.c#L2147 curseg->zone = GET_ZONE_FROM_SEG(sbi, curseg->segno); If secs_per_zone is corrupted due to fuzzing test, it will cause divide zero operation when using GET_ZONE_FROM_SEG macro, so we should do more sanity check with secs_per_zone during mount to avoid this issue. Signed-off-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch adds to do sanity check with {sit,nat}_ver_bitmap_bytesize during mount, in order to avoid accessing across cache boundary with this abnormal bitmap size. - Overview buffer overrun in build_sit_info() when mounting a crafted f2fs image - Reproduce - Kernel message [ 548.580867] F2FS-fs (loop0): Invalid log blocks per segment (8201) [ 548.580877] F2FS-fs (loop0): Can't find valid F2FS filesystem in 1th superblock [ 548.584979] ================================================================== [ 548.586568] BUG: KASAN: use-after-free in kmemdup+0x36/0x50 [ 548.587715] Read of size 64 at addr ffff8801e9c265ff by task mount/1295 [ 548.589428] CPU: 1 PID: 1295 Comm: mount Not tainted 4.18.0-rc1+ #4 [ 548.589432] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 [ 548.589438] Call Trace: [ 548.589474] dump_stack+0x7b/0xb5 [ 548.589487] print_address_description+0x70/0x290 [ 548.589492] kasan_report+0x291/0x390 [ 548.589496] ? kmemdup+0x36/0x50 [ 548.589509] check_memory_region+0x139/0x190 [ 548.589514] memcpy+0x23/0x50 [ 548.589518] kmemdup+0x36/0x50 [ 548.589545] f2fs_build_segment_manager+0x8fa/0x3410 [ 548.589551] ? __asan_loadN+0xf/0x20 [ 548.589560] ? f2fs_sanity_check_ckpt+0x1be/0x240 [ 548.589566] ? f2fs_flush_sit_entries+0x10c0/0x10c0 [ 548.589587] ? __put_user_ns+0x40/0x40 [ 548.589604] ? find_next_bit+0x57/0x90 [ 548.589610] f2fs_fill_super+0x194b/0x2b40 [ 548.589617] ? f2fs_commit_super+0x1b0/0x1b0 [ 548.589637] ? set_blocksize+0x90/0x140 [ 548.589651] mount_bdev+0x1c5/0x210 [ 548.589655] ? f2fs_commit_super+0x1b0/0x1b0 [ 548.589667] f2fs_mount+0x15/0x20 [ 548.589672] mount_fs+0x60/0x1a0 [ 548.589683] ? alloc_vfsmnt+0x309/0x360 [ 548.589688] vfs_kern_mount+0x6b/0x1a0 [ 548.589699] do_mount+0x34a/0x18c0 [ 548.589710] ? lockref_put_or_lock+0xcf/0x160 [ 548.589716] ? copy_mount_string+0x20/0x20 [ 548.589728] ? memcg_kmem_put_cache+0x1b/0xa0 [ 548.589734] ? kasan_check_write+0x14/0x20 [ 548.589740] ? _copy_from_user+0x6a/0x90 [ 548.589744] ? memdup_user+0x42/0x60 [ 548.589750] ksys_mount+0x83/0xd0 [ 548.589755] __x64_sys_mount+0x67/0x80 [ 548.589781] do_syscall_64+0x78/0x170 [ 548.589797] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 548.589820] RIP: 0033:0x7f76fc331b9a [ 548.589821] Code: 48 8b 0d 01 c3 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d ce c2 2b 00 f7 d8 64 89 01 48 [ 548.589880] RSP: 002b:00007ffd4f0a0e48 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5 [ 548.589890] RAX: ffffffffffffffda RBX: 000000000146c030 RCX: 00007f76fc331b9a [ 548.589892] RDX: 000000000146c210 RSI: 000000000146df30 RDI: 0000000001474ec0 [ 548.589895] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000013 [ 548.589897] R10: 00000000c0ed0000 R11: 0000000000000206 R12: 0000000001474ec0 [ 548.589900] R13: 000000000146c210 R14: 0000000000000000 R15: 0000000000000003 [ 548.590242] The buggy address belongs to the page: [ 548.591243] page:ffffea0007a70980 count:0 mapcount:0 mapping:0000000000000000 index:0x0 [ 548.592886] flags: 0x2ffff0000000000() [ 548.593665] raw: 02ffff0000000000 dead000000000100 dead000000000200 0000000000000000 [ 548.595258] raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 [ 548.603713] page dumped because: kasan: bad access detected [ 548.605203] Memory state around the buggy address: [ 548.606198] ffff8801e9c26480: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 548.607676] ffff8801e9c26500: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 548.609157] >ffff8801e9c26580: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 548.610629] ^ [ 548.612088] ffff8801e9c26600: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 548.613674] ffff8801e9c26680: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 548.615141] ================================================================== [ 548.616613] Disabling lock debugging due to kernel taint [ 548.622871] WARNING: CPU: 1 PID: 1295 at mm/page_alloc.c:4065 __alloc_pages_slowpath+0xe4a/0x1420 [ 548.622878] Modules linked in: snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hwdep snd_hda_core snd_pcm snd_timer snd mac_hid i2c_piix4 soundcore ib_iser rdma_cm iw_cm ib_cm ib_core iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx raid1 raid0 multipath linear 8139too crct10dif_pclmul crc32_pclmul qxl drm_kms_helper syscopyarea aesni_intel sysfillrect sysimgblt fb_sys_fops ttm drm aes_x86_64 crypto_simd cryptd 8139cp glue_helper mii pata_acpi floppy [ 548.623217] CPU: 1 PID: 1295 Comm: mount Tainted: G B 4.18.0-rc1+ #4 [ 548.623219] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 [ 548.623226] RIP: 0010:__alloc_pages_slowpath+0xe4a/0x1420 [ 548.623227] Code: ff ff 01 89 85 c8 fe ff ff e9 91 fc ff ff 41 89 c5 e9 5c fc ff ff 0f 0b 89 f8 25 ff ff f7 ff 89 85 8c fe ff ff e9 d5 f2 ff ff <0f> 0b e9 65 f2 ff ff 65 8b 05 38 81 d2 47 f6 c4 01 74 1c 65 48 8b [ 548.623281] RSP: 0018:ffff8801f28c7678 EFLAGS: 00010246 [ 548.623284] RAX: 0000000000000000 RBX: 00000000006040c0 RCX: ffffffffb82f73b7 [ 548.623287] RDX: 1ffff1003e518eeb RSI: 000000000000000c RDI: 0000000000000000 [ 548.623290] RBP: ffff8801f28c7880 R08: 0000000000000000 R09: ffffed0047fff2c5 [ 548.623292] R10: 0000000000000001 R11: ffffed0047fff2c4 R12: ffff8801e88de040 [ 548.623295] R13: 00000000006040c0 R14: 000000000000000c R15: ffff8801f28c7938 [ 548.623299] FS: 00007f76fca51840(0000) GS:ffff8801f6f00000(0000) knlGS:0000000000000000 [ 548.623302] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 548.623304] CR2: 00007f19b9171760 CR3: 00000001ed952000 CR4: 00000000000006e0 [ 548.623317] Call Trace: [ 548.623325] ? kasan_check_read+0x11/0x20 [ 548.623330] ? __zone_watermark_ok+0x92/0x240 [ 548.623336] ? get_page_from_freelist+0x1c3/0x1d90 [ 548.623347] ? _raw_spin_lock_irqsave+0x2a/0x60 [ 548.623353] ? warn_alloc+0x250/0x250 [ 548.623358] ? save_stack+0x46/0xd0 [ 548.623361] ? kasan_kmalloc+0xad/0xe0 [ 548.623366] ? __isolate_free_page+0x2a0/0x2a0 [ 548.623370] ? mount_fs+0x60/0x1a0 [ 548.623374] ? vfs_kern_mount+0x6b/0x1a0 [ 548.623378] ? do_mount+0x34a/0x18c0 [ 548.623383] ? ksys_mount+0x83/0xd0 [ 548.623387] ? __x64_sys_mount+0x67/0x80 [ 548.623391] ? do_syscall_64+0x78/0x170 [ 548.623396] ? entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 548.623401] __alloc_pages_nodemask+0x3c5/0x400 [ 548.623407] ? __alloc_pages_slowpath+0x1420/0x1420 [ 548.623412] ? __mutex_lock_slowpath+0x20/0x20 [ 548.623417] ? kvmalloc_node+0x31/0x80 [ 548.623424] alloc_pages_current+0x75/0x110 [ 548.623436] kmalloc_order+0x24/0x60 [ 548.623442] kmalloc_order_trace+0x24/0xb0 [ 548.623448] __kmalloc_track_caller+0x207/0x220 [ 548.623455] ? f2fs_build_node_manager+0x399/0xbb0 [ 548.623460] kmemdup+0x20/0x50 [ 548.623465] f2fs_build_node_manager+0x399/0xbb0 [ 548.623470] f2fs_fill_super+0x195e/0x2b40 [ 548.623477] ? f2fs_commit_super+0x1b0/0x1b0 [ 548.623481] ? set_blocksize+0x90/0x140 [ 548.623486] mount_bdev+0x1c5/0x210 [ 548.623489] ? f2fs_commit_super+0x1b0/0x1b0 [ 548.623495] f2fs_mount+0x15/0x20 [ 548.623498] mount_fs+0x60/0x1a0 [ 548.623503] ? alloc_vfsmnt+0x309/0x360 [ 548.623508] vfs_kern_mount+0x6b/0x1a0 [ 548.623513] do_mount+0x34a/0x18c0 [ 548.623518] ? lockref_put_or_lock+0xcf/0x160 [ 548.623523] ? copy_mount_string+0x20/0x20 [ 548.623528] ? memcg_kmem_put_cache+0x1b/0xa0 [ 548.623533] ? kasan_check_write+0x14/0x20 [ 548.623537] ? _copy_from_user+0x6a/0x90 [ 548.623542] ? memdup_user+0x42/0x60 [ 548.623547] ksys_mount+0x83/0xd0 [ 548.623552] __x64_sys_mount+0x67/0x80 [ 548.623557] do_syscall_64+0x78/0x170 [ 548.623562] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 548.623566] RIP: 0033:0x7f76fc331b9a [ 548.623567] Code: 48 8b 0d 01 c3 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d ce c2 2b 00 f7 d8 64 89 01 48 [ 548.623632] RSP: 002b:00007ffd4f0a0e48 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5 [ 548.623636] RAX: ffffffffffffffda RBX: 000000000146c030 RCX: 00007f76fc331b9a [ 548.623639] RDX: 000000000146c210 RSI: 000000000146df30 RDI: 0000000001474ec0 [ 548.623641] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000013 [ 548.623643] R10: 00000000c0ed0000 R11: 0000000000000206 R12: 0000000001474ec0 [ 548.623646] R13: 000000000146c210 R14: 0000000000000000 R15: 0000000000000003 [ 548.623650] ---[ end trace 4ce02f25ff7d3df5 ]--- [ 548.623656] F2FS-fs (loop0): Failed to initialize F2FS node manager [ 548.627936] F2FS-fs (loop0): Invalid log blocks per segment (8201) [ 548.627940] F2FS-fs (loop0): Can't find valid F2FS filesystem in 1th superblock [ 548.635835] F2FS-fs (loop0): Failed to initialize F2FS node manager - Location https://elixir.bootlin.com/linux/v4.18-rc1/source/fs/f2fs/segment.c#L3578 sit_i->sit_bitmap = kmemdup(src_bitmap, bitmap_size, GFP_KERNEL); Buffer overrun happens when doing memcpy. I suspect there is missing (inconsistent) checks on bitmap_size. Reported by Wen Xu (wen.xu@gatech.edu) from SSLab, Gatech. Reported-by: Wen Xu <wen.xu@gatech.edu> Signed-off-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

If FI_EXTRA_ATTR is set in inode by fuzzing, inode.i_addr[0] will be parsed as inode.i_extra_isize, then in __recover_inline_status, inline data address will beyond boundary of page, result in accessing invalid memory. So in this condition, during reading inode page, let's do sanity check with EXTRA_ATTR feature of fs and extra_attr bit of inode, if they're inconsistent, deny to load this inode. - Overview Out-of-bound access in f2fs_iget() when mounting a corrupted f2fs image - Reproduce The following message will be got in KASAN build of 4.18 upstream kernel. [ 819.392227] ================================================================== [ 819.393901] BUG: KASAN: slab-out-of-bounds in f2fs_iget+0x736/0x1530 [ 819.395329] Read of size 4 at addr ffff8801f099c968 by task mount/1292 [ 819.397079] CPU: 1 PID: 1292 Comm: mount Not tainted 4.18.0-rc1+ #4 [ 819.397082] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 [ 819.397088] Call Trace: [ 819.397124] dump_stack+0x7b/0xb5 [ 819.397154] print_address_description+0x70/0x290 [ 819.397159] kasan_report+0x291/0x390 [ 819.397163] ? f2fs_iget+0x736/0x1530 [ 819.397176] check_memory_region+0x139/0x190 [ 819.397182] __asan_loadN+0xf/0x20 [ 819.397185] f2fs_iget+0x736/0x1530 [ 819.397197] f2fs_fill_super+0x1b4f/0x2b40 [ 819.397202] ? f2fs_fill_super+0x1b4f/0x2b40 [ 819.397208] ? f2fs_commit_super+0x1b0/0x1b0 [ 819.397227] ? set_blocksize+0x90/0x140 [ 819.397241] mount_bdev+0x1c5/0x210 [ 819.397245] ? f2fs_commit_super+0x1b0/0x1b0 [ 819.397252] f2fs_mount+0x15/0x20 [ 819.397256] mount_fs+0x60/0x1a0 [ 819.397267] ? alloc_vfsmnt+0x309/0x360 [ 819.397272] vfs_kern_mount+0x6b/0x1a0 [ 819.397282] do_mount+0x34a/0x18c0 [ 819.397300] ? lockref_put_or_lock+0xcf/0x160 [ 819.397306] ? copy_mount_string+0x20/0x20 [ 819.397318] ? memcg_kmem_put_cache+0x1b/0xa0 [ 819.397324] ? kasan_check_write+0x14/0x20 [ 819.397334] ? _copy_from_user+0x6a/0x90 [ 819.397353] ? memdup_user+0x42/0x60 [ 819.397359] ksys_mount+0x83/0xd0 [ 819.397365] __x64_sys_mount+0x67/0x80 [ 819.397388] do_syscall_64+0x78/0x170 [ 819.397403] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 819.397422] RIP: 0033:0x7f54c667cb9a [ 819.397424] Code: 48 8b 0d 01 c3 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d ce c2 2b 00 f7 d8 64 89 01 48 [ 819.397483] RSP: 002b:00007ffd8f46cd08 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5 [ 819.397496] RAX: ffffffffffffffda RBX: 0000000000dfa030 RCX: 00007f54c667cb9a [ 819.397498] RDX: 0000000000dfa210 RSI: 0000000000dfbf30 RDI: 0000000000e02ec0 [ 819.397501] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000013 [ 819.397503] R10: 00000000c0ed0000 R11: 0000000000000202 R12: 0000000000e02ec0 [ 819.397505] R13: 0000000000dfa210 R14: 0000000000000000 R15: 0000000000000003 [ 819.397866] Allocated by task 139: [ 819.398702] save_stack+0x46/0xd0 [ 819.398705] kasan_kmalloc+0xad/0xe0 [ 819.398709] kasan_slab_alloc+0x11/0x20 [ 819.398713] kmem_cache_alloc+0xd1/0x1e0 [ 819.398717] dup_fd+0x50/0x4c0 [ 819.398740] copy_process.part.37+0xbed/0x32e0 [ 819.398744] _do_fork+0x16e/0x590 [ 819.398748] __x64_sys_clone+0x69/0x80 [ 819.398752] do_syscall_64+0x78/0x170 [ 819.398756] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 819.399097] Freed by task 159: [ 819.399743] save_stack+0x46/0xd0 [ 819.399747] __kasan_slab_free+0x13c/0x1a0 [ 819.399750] kasan_slab_free+0xe/0x10 [ 819.399754] kmem_cache_free+0x89/0x1e0 [ 819.399757] put_files_struct+0x132/0x150 [ 819.399761] exit_files+0x62/0x70 [ 819.399766] do_exit+0x47b/0x1390 [ 819.399770] do_group_exit+0x86/0x130 [ 819.399774] __x64_sys_exit_group+0x2c/0x30 [ 819.399778] do_syscall_64+0x78/0x170 [ 819.399782] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 819.400115] The buggy address belongs to the object at ffff8801f099c680 which belongs to the cache files_cache of size 704 [ 819.403234] The buggy address is located 40 bytes to the right of 704-byte region [ffff8801f099c680, ffff8801f099c940) [ 819.405689] The buggy address belongs to the page: [ 819.406709] page:ffffea0007c26700 count:1 mapcount:0 mapping:ffff8801f69a3340 index:0xffff8801f099d380 compound_mapcount: 0 [ 819.408984] flags: 0x2ffff0000008100(slab|head) [ 819.409932] raw: 02ffff0000008100 ffffea00077fb600 0000000200000002 ffff8801f69a3340 [ 819.411514] raw: ffff8801f099d380 0000000080130000 00000001ffffffff 0000000000000000 [ 819.413073] page dumped because: kasan: bad access detected [ 819.414539] Memory state around the buggy address: [ 819.415521] ffff8801f099c800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 819.416981] ffff8801f099c880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 819.418454] >ffff8801f099c900: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 819.419921] ^ [ 819.421265] ffff8801f099c980: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 819.422745] ffff8801f099ca00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 819.424206] ================================================================== [ 819.425668] Disabling lock debugging due to kernel taint [ 819.457463] F2FS-fs (loop0): Mounted with checkpoint version = 3 The kernel still mounts the image. If you run the following program on the mounted folder mnt, (poc.c) static void activity(char *mpoint) { char *foo_bar_baz; int err; static int buf[8192]; memset(buf, 0, sizeof(buf)); err = asprintf(&foo_bar_baz, "%s/foo/bar/baz", mpoint); int fd = open(foo_bar_baz, O_RDONLY, 0); if (fd >= 0) { read(fd, (char *)buf, 11); close(fd); } } int main(int argc, char *argv[]) { activity(argv[1]); return 0; } You can get kernel crash: [ 819.457463] F2FS-fs (loop0): Mounted with checkpoint version = 3 [ 918.028501] BUG: unable to handle kernel paging request at ffffed0048000d82 [ 918.044020] PGD 23ffee067 P4D 23ffee067 PUD 23fbef067 PMD 0 [ 918.045207] Oops: 0000 [#1] SMP KASAN PTI [ 918.046048] CPU: 0 PID: 1309 Comm: poc Tainted: G B 4.18.0-rc1+ #4 [ 918.047573] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 [ 918.049552] RIP: 0010:check_memory_region+0x5e/0x190 [ 918.050565] Code: f8 49 c1 e8 03 49 89 db 49 c1 eb 03 4d 01 cb 4d 01 c1 4d 8d 63 01 4c 89 c8 4d 89 e2 4d 29 ca 49 83 fa 10 7f 3d 4d 85 d2 74 32 <41> 80 39 00 75 23 48 b8 01 00 00 00 00 fc ff df 4d 01 d1 49 01 c0 [ 918.054322] RSP: 0018:ffff8801e3a1f258 EFLAGS: 00010202 [ 918.055400] RAX: ffffed0048000d82 RBX: ffff880240006c11 RCX: ffffffffb8867d14 [ 918.056832] RDX: 0000000000000000 RSI: 0000000000000002 RDI: ffff880240006c10 [ 918.058253] RBP: ffff8801e3a1f268 R08: 1ffff10048000d82 R09: ffffed0048000d82 [ 918.059717] R10: 0000000000000001 R11: ffffed0048000d82 R12: ffffed0048000d83 [ 918.061159] R13: ffff8801e3a1f390 R14: 0000000000000000 R15: ffff880240006c08 [ 918.062614] FS: 00007fac9732c700(0000) GS:ffff8801f6e00000(0000) knlGS:0000000000000000 [ 918.064246] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 918.065412] CR2: ffffed0048000d82 CR3: 00000001df77a000 CR4: 00000000000006f0 [ 918.066882] Call Trace: [ 918.067410] __asan_loadN+0xf/0x20 [ 918.068149] f2fs_find_target_dentry+0xf4/0x270 [ 918.069083] ? __get_node_page+0x331/0x5b0 [ 918.069925] f2fs_find_in_inline_dir+0x24b/0x310 [ 918.070881] ? f2fs_recover_inline_data+0x4c0/0x4c0 [ 918.071905] ? unwind_next_frame.part.5+0x34f/0x490 [ 918.072901] ? unwind_dump+0x290/0x290 [ 918.073695] ? is_bpf_text_address+0xe/0x20 [ 918.074566] __f2fs_find_entry+0x599/0x670 [ 918.075408] ? kasan_unpoison_shadow+0x36/0x50 [ 918.076315] ? kasan_kmalloc+0xad/0xe0 [ 918.077100] ? memcg_kmem_put_cache+0x55/0xa0 [ 918.077998] ? f2fs_find_target_dentry+0x270/0x270 [ 918.079006] ? d_set_d_op+0x30/0x100 [ 918.079749] ? __d_lookup_rcu+0x69/0x2e0 [ 918.080556] ? __d_alloc+0x275/0x450 [ 918.081297] ? kasan_check_write+0x14/0x20 [ 918.082135] ? memset+0x31/0x40 [ 918.082820] ? fscrypt_setup_filename+0x1ec/0x4c0 [ 918.083782] ? d_alloc_parallel+0x5bb/0x8c0 [ 918.084640] f2fs_find_entry+0xe9/0x110 [ 918.085432] ? __f2fs_find_entry+0x670/0x670 [ 918.086308] ? kasan_check_write+0x14/0x20 [ 918.087163] f2fs_lookup+0x297/0x590 [ 918.087902] ? f2fs_link+0x2b0/0x2b0 [ 918.088646] ? legitimize_path.isra.29+0x61/0xa0 [ 918.089589] __lookup_slow+0x12e/0x240 [ 918.090371] ? may_delete+0x2b0/0x2b0 [ 918.091123] ? __nd_alloc_stack+0xa0/0xa0 [ 918.091944] lookup_slow+0x44/0x60 [ 918.092642] walk_component+0x3ee/0xa40 [ 918.093428] ? is_bpf_text_address+0xe/0x20 [ 918.094283] ? pick_link+0x3e0/0x3e0 [ 918.095047] ? in_group_p+0xa5/0xe0 [ 918.095771] ? generic_permission+0x53/0x1e0 [ 918.096666] ? security_inode_permission+0x1d/0x70 [ 918.097646] ? inode_permission+0x7a/0x1f0 [ 918.098497] link_path_walk+0x2a2/0x7b0 [ 918.099298] ? apparmor_capget+0x3d0/0x3d0 [ 918.100140] ? walk_component+0xa40/0xa40 [ 918.100958] ? path_init+0x2e6/0x580 [ 918.101695] path_openat+0x1bb/0x2160 [ 918.102471] ? __save_stack_trace+0x92/0x100 [ 918.103352] ? save_stack+0xb5/0xd0 [ 918.104070] ? vfs_unlink+0x250/0x250 [ 918.104822] ? save_stack+0x46/0xd0 [ 918.105538] ? kasan_slab_alloc+0x11/0x20 [ 918.106370] ? kmem_cache_alloc+0xd1/0x1e0 [ 918.107213] ? getname_flags+0x76/0x2c0 [ 918.107997] ? getname+0x12/0x20 [ 918.108677] ? do_sys_open+0x14b/0x2c0 [ 918.109450] ? __x64_sys_open+0x4c/0x60 [ 918.110255] ? do_syscall_64+0x78/0x170 [ 918.111083] ? entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 918.112148] ? entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 918.113204] ? f2fs_empty_inline_dir+0x1e0/0x1e0 [ 918.114150] ? timespec64_trunc+0x5c/0x90 [ 918.114993] ? wb_io_lists_depopulated+0x1a/0xc0 [ 918.115937] ? inode_io_list_move_locked+0x102/0x110 [ 918.116949] do_filp_open+0x12b/0x1d0 [ 918.117709] ? may_open_dev+0x50/0x50 [ 918.118475] ? kasan_kmalloc+0xad/0xe0 [ 918.119246] do_sys_open+0x17c/0x2c0 [ 918.119983] ? do_sys_open+0x17c/0x2c0 [ 918.120751] ? filp_open+0x60/0x60 [ 918.121463] ? task_work_run+0x4d/0xf0 [ 918.122237] __x64_sys_open+0x4c/0x60 [ 918.123001] do_syscall_64+0x78/0x170 [ 918.123759] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 918.124802] RIP: 0033:0x7fac96e3e040 [ 918.125537] Code: 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 83 3d 09 27 2d 00 00 75 10 b8 02 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 7e e0 01 00 48 89 04 24 [ 918.129341] RSP: 002b:00007fff1b37f848 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 [ 918.130870] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fac96e3e040 [ 918.132295] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000000122d080 [ 918.133748] RBP: 00007fff1b37f9b0 R08: 00007fac9710bbd8 R09: 0000000000000001 [ 918.135209] R10: 000000000000069d R11: 0000000000000246 R12: 0000000000400c20 [ 918.136650] R13: 00007fff1b37fab0 R14: 0000000000000000 R15: 0000000000000000 [ 918.138093] Modules linked in: snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hwdep snd_hda_core snd_pcm snd_timer snd mac_hid i2c_piix4 soundcore ib_iser rdma_cm iw_cm ib_cm ib_core iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx raid1 raid0 multipath linear 8139too crct10dif_pclmul crc32_pclmul qxl drm_kms_helper syscopyarea aesni_intel sysfillrect sysimgblt fb_sys_fops ttm drm aes_x86_64 crypto_simd cryptd 8139cp glue_helper mii pata_acpi floppy [ 918.147924] CR2: ffffed0048000d82 [ 918.148619] ---[ end trace 4ce02f25ff7d3df5 ]--- [ 918.149563] RIP: 0010:check_memory_region+0x5e/0x190 [ 918.150576] Code: f8 49 c1 e8 03 49 89 db 49 c1 eb 03 4d 01 cb 4d 01 c1 4d 8d 63 01 4c 89 c8 4d 89 e2 4d 29 ca 49 83 fa 10 7f 3d 4d 85 d2 74 32 <41> 80 39 00 75 23 48 b8 01 00 00 00 00 fc ff df 4d 01 d1 49 01 c0 [ 918.154360] RSP: 0018:ffff8801e3a1f258 EFLAGS: 00010202 [ 918.155411] RAX: ffffed0048000d82 RBX: ffff880240006c11 RCX: ffffffffb8867d14 [ 918.156833] RDX: 0000000000000000 RSI: 0000000000000002 RDI: ffff880240006c10 [ 918.158257] RBP: ffff8801e3a1f268 R08: 1ffff10048000d82 R09: ffffed0048000d82 [ 918.159722] R10: 0000000000000001 R11: ffffed0048000d82 R12: ffffed0048000d83 [ 918.161149] R13: ffff8801e3a1f390 R14: 0000000000000000 R15: ffff880240006c08 [ 918.162587] FS: 00007fac9732c700(0000) GS:ffff8801f6e00000(0000) knlGS:0000000000000000 [ 918.164203] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 918.165356] CR2: ffffed0048000d82 CR3: 00000001df77a000 CR4: 00000000000006f0 Reported-by: Wen Xu <wen.xu@gatech.edu> Signed-off-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch fixs to do sanity check with user_block_count. - Overview Divide zero in utilization when mount() a corrupted f2fs image - Reproduce (4.18 upstream kernel) - Kernel message [ 564.099503] F2FS-fs (loop0): invalid crc value [ 564.101991] divide error: 0000 [#1] SMP KASAN PTI [ 564.103103] CPU: 1 PID: 1298 Comm: f2fs_discard-7: Not tainted 4.18.0-rc1+ #4 [ 564.104584] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 [ 564.106624] RIP: 0010:issue_discard_thread+0x248/0x5c0 [ 564.107692] Code: ff ff 48 8b bd e8 fe ff ff 41 8b 9d 4c 04 00 00 e8 cd b8 ad ff 41 8b 85 50 04 00 00 31 d2 48 8d 04 80 48 8d 04 80 48 c1 e0 02 <48> f7 f3 83 f8 50 7e 16 41 c7 86 7c ff ff ff 01 00 00 00 41 c7 86 [ 564.111686] RSP: 0018:ffff8801f3117dc0 EFLAGS: 00010206 [ 564.112775] RAX: 0000000000000384 RBX: 0000000000000000 RCX: ffffffffb88c1e03 [ 564.114250] RDX: 0000000000000000 RSI: dffffc0000000000 RDI: ffff8801e3aa4850 [ 564.115706] RBP: ffff8801f3117f00 R08: 1ffffffff751a1d0 R09: fffffbfff751a1d0 [ 564.117177] R10: 0000000000000001 R11: fffffbfff751a1d0 R12: 00000000fffffffc [ 564.118634] R13: ffff8801e3aa4400 R14: ffff8801f3117ed8 R15: ffff8801e2050000 [ 564.120094] FS: 0000000000000000(0000) GS:ffff8801f6f00000(0000) knlGS:0000000000000000 [ 564.121748] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 564.122923] CR2: 000000000202b078 CR3: 00000001f11ac000 CR4: 00000000000006e0 [ 564.124383] Call Trace: [ 564.124924] ? __issue_discard_cmd+0x480/0x480 [ 564.125882] ? __sched_text_start+0x8/0x8 [ 564.126756] ? __kthread_parkme+0xcb/0x100 [ 564.127620] ? kthread_blkcg+0x70/0x70 [ 564.128412] kthread+0x180/0x1d0 [ 564.129105] ? __issue_discard_cmd+0x480/0x480 [ 564.130029] ? kthread_associate_blkcg+0x150/0x150 [ 564.131033] ret_from_fork+0x35/0x40 [ 564.131794] Modules linked in: snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hwdep snd_hda_core snd_pcm snd_timer snd mac_hid i2c_piix4 soundcore ib_iser rdma_cm iw_cm ib_cm ib_core iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx raid1 raid0 multipath linear 8139too crct10dif_pclmul crc32_pclmul qxl drm_kms_helper syscopyarea aesni_intel sysfillrect sysimgblt fb_sys_fops ttm drm aes_x86_64 crypto_simd cryptd 8139cp glue_helper mii pata_acpi floppy [ 564.141798] ---[ end trace 4ce02f25ff7d3df5 ]--- [ 564.142773] RIP: 0010:issue_discard_thread+0x248/0x5c0 [ 564.143885] Code: ff ff 48 8b bd e8 fe ff ff 41 8b 9d 4c 04 00 00 e8 cd b8 ad ff 41 8b 85 50 04 00 00 31 d2 48 8d 04 80 48 8d 04 80 48 c1 e0 02 <48> f7 f3 83 f8 50 7e 16 41 c7 86 7c ff ff ff 01 00 00 00 41 c7 86 [ 564.147776] RSP: 0018:ffff8801f3117dc0 EFLAGS: 00010206 [ 564.148856] RAX: 0000000000000384 RBX: 0000000000000000 RCX: ffffffffb88c1e03 [ 564.150424] RDX: 0000000000000000 RSI: dffffc0000000000 RDI: ffff8801e3aa4850 [ 564.151906] RBP: ffff8801f3117f00 R08: 1ffffffff751a1d0 R09: fffffbfff751a1d0 [ 564.153463] R10: 0000000000000001 R11: fffffbfff751a1d0 R12: 00000000fffffffc [ 564.154915] R13: ffff8801e3aa4400 R14: ffff8801f3117ed8 R15: ffff8801e2050000 [ 564.156405] FS: 0000000000000000(0000) GS:ffff8801f6f00000(0000) knlGS:0000000000000000 [ 564.158070] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 564.159279] CR2: 000000000202b078 CR3: 00000001f11ac000 CR4: 00000000000006e0 [ 564.161043] ================================================================== [ 564.162587] BUG: KASAN: stack-out-of-bounds in from_kuid_munged+0x1d/0x50 [ 564.163994] Read of size 4 at addr ffff8801f3117c84 by task f2fs_discard-7:/1298 [ 564.165852] CPU: 1 PID: 1298 Comm: f2fs_discard-7: Tainted: G D 4.18.0-rc1+ #4 [ 564.167593] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 [ 564.169522] Call Trace: [ 564.170057] dump_stack+0x7b/0xb5 [ 564.170778] print_address_description+0x70/0x290 [ 564.171765] kasan_report+0x291/0x390 [ 564.172540] ? from_kuid_munged+0x1d/0x50 [ 564.173408] __asan_load4+0x78/0x80 [ 564.174148] from_kuid_munged+0x1d/0x50 [ 564.174962] do_notify_parent+0x1f5/0x4f0 [ 564.175808] ? send_sigqueue+0x390/0x390 [ 564.176639] ? css_set_move_task+0x152/0x340 [ 564.184197] do_exit+0x1290/0x1390 [ 564.184950] ? __issue_discard_cmd+0x480/0x480 [ 564.185884] ? mm_update_next_owner+0x380/0x380 [ 564.186829] ? __sched_text_start+0x8/0x8 [ 564.187672] ? __kthread_parkme+0xcb/0x100 [ 564.188528] ? kthread_blkcg+0x70/0x70 [ 564.189333] ? kthread+0x180/0x1d0 [ 564.190052] ? __issue_discard_cmd+0x480/0x480 [ 564.190983] rewind_stack_do_exit+0x17/0x20 [ 564.192190] The buggy address belongs to the page: [ 564.193213] page:ffffea0007cc45c0 count:0 mapcount:0 mapping:0000000000000000 index:0x0 [ 564.194856] flags: 0x2ffff0000000000() [ 564.195644] raw: 02ffff0000000000 0000000000000000 dead000000000200 0000000000000000 [ 564.197247] raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 [ 564.198826] page dumped because: kasan: bad access detected [ 564.200299] Memory state around the buggy address: [ 564.201306] ffff8801f3117b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 564.202779] ffff8801f3117c00: 00 00 00 00 00 00 00 00 00 00 00 f3 f3 f3 f3 f3 [ 564.204252] >ffff8801f3117c80: f3 f3 f3 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1 [ 564.205742] ^ [ 564.206424] ffff8801f3117d00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 564.207908] ffff8801f3117d80: f3 f3 f3 f3 f3 f3 f3 f3 00 00 00 00 00 00 00 00 [ 564.209389] ================================================================== [ 564.231795] F2FS-fs (loop0): Mounted with checkpoint version = 2 - Location https://elixir.bootlin.com/linux/v4.18-rc1/source/fs/f2fs/segment.h#L586 return div_u64((u64)valid_user_blocks(sbi) * 100, sbi->user_block_count); Missing checks on sbi->user_block_count. Reported-by: Wen Xu <wen.xu@gatech.edu> Signed-off-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch adds to do sanity check with below fields of inode to avoid reported panic. - node footer - iblocks https://bugzilla.kernel.org/show_bug.cgi?id=200223 - Overview BUG() triggered in f2fs_truncate_inode_blocks() when un-mounting a mounted f2fs image after writing to it - Reproduce - POC (poc.c) static void activity(char *mpoint) { char *foo_bar_baz; int err; static int buf[8192]; memset(buf, 0, sizeof(buf)); err = asprintf(&foo_bar_baz, "%s/foo/bar/baz", mpoint); // open / write / read int fd = open(foo_bar_baz, O_RDWR | O_TRUNC, 0777); if (fd >= 0) { write(fd, (char *)buf, 517); write(fd, (char *)buf, sizeof(buf)); close(fd); } } int main(int argc, char *argv[]) { activity(argv[1]); return 0; } - Kernel meesage [ 552.479723] F2FS-fs (loop0): Mounted with checkpoint version = 2 [ 556.451891] ------------[ cut here ]------------ [ 556.451899] kernel BUG at fs/f2fs/node.c:987! [ 556.452920] invalid opcode: 0000 [#1] SMP KASAN PTI [ 556.453936] CPU: 1 PID: 1310 Comm: umount Not tainted 4.18.0-rc1+ #4 [ 556.455213] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 [ 556.457140] RIP: 0010:f2fs_truncate_inode_blocks+0x4a7/0x6f0 [ 556.458280] Code: e8 ae ea ff ff 41 89 c7 c1 e8 1f 84 c0 74 0a 41 83 ff fe 0f 85 35 ff ff ff 81 85 b0 fe ff ff fb 03 00 00 e9 f7 fd ff ff 0f 0b <0f> 0b e8 62 b7 9a 00 48 8b bd a0 fe ff ff e8 56 54 ae ff 48 8b b5 [ 556.462015] RSP: 0018:ffff8801f292f808 EFLAGS: 00010286 [ 556.463068] RAX: ffffed003e73242d RBX: ffff8801f292f958 RCX: ffffffffb88b81bc [ 556.464479] RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff8801f3992164 [ 556.465901] RBP: ffff8801f292f980 R08: ffffed003e73242d R09: ffffed003e73242d [ 556.467311] R10: 0000000000000001 R11: ffffed003e73242c R12: 00000000fffffc64 [ 556.468706] R13: ffff8801f3992000 R14: 0000000000000058 R15: 00000000ffff8801 [ 556.470117] FS: 00007f8029297840(0000) GS:ffff8801f6f00000(0000) knlGS:0000000000000000 [ 556.471702] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 556.472838] CR2: 000055f5f57305d8 CR3: 00000001f18b0000 CR4: 00000000000006e0 [ 556.474265] Call Trace: [ 556.474782] ? f2fs_alloc_nid_failed+0xf0/0xf0 [ 556.475686] ? truncate_nodes+0x980/0x980 [ 556.476516] ? pagecache_get_page+0x21f/0x2f0 [ 556.477412] ? __asan_loadN+0xf/0x20 [ 556.478153] ? __get_node_page+0x331/0x5b0 [ 556.478992] ? reweight_entity+0x1e6/0x3b0 [ 556.479826] f2fs_truncate_blocks+0x55e/0x740 [ 556.480709] ? f2fs_truncate_data_blocks+0x20/0x20 [ 556.481689] ? __radix_tree_lookup+0x34/0x160 [ 556.482630] ? radix_tree_lookup+0xd/0x10 [ 556.483445] f2fs_truncate+0xd4/0x1a0 [ 556.484206] f2fs_evict_inode+0x5ce/0x630 [ 556.485032] evict+0x16f/0x290 [ 556.485664] iput+0x280/0x300 [ 556.486300] dentry_unlink_inode+0x165/0x1e0 [ 556.487169] __dentry_kill+0x16a/0x260 [ 556.487936] dentry_kill+0x70/0x250 [ 556.488651] shrink_dentry_list+0x125/0x260 [ 556.489504] shrink_dcache_parent+0xc1/0x110 [ 556.490379] ? shrink_dcache_sb+0x200/0x200 [ 556.491231] ? bit_wait_timeout+0xc0/0xc0 [ 556.492047] do_one_tree+0x12/0x40 [ 556.492743] shrink_dcache_for_umount+0x3f/0xa0 [ 556.493656] generic_shutdown_super+0x43/0x1c0 [ 556.494561] kill_block_super+0x52/0x80 [ 556.495341] kill_f2fs_super+0x62/0x70 [ 556.496105] deactivate_locked_super+0x6f/0xa0 [ 556.497004] deactivate_super+0x5e/0x80 [ 556.497785] cleanup_mnt+0x61/0xa0 [ 556.498492] __cleanup_mnt+0x12/0x20 [ 556.499218] task_work_run+0xc8/0xf0 [ 556.499949] exit_to_usermode_loop+0x125/0x130 [ 556.500846] do_syscall_64+0x138/0x170 [ 556.501609] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 556.502659] RIP: 0033:0x7f8028b77487 [ 556.503384] Code: 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e1 c9 2b 00 f7 d8 64 89 01 48 [ 556.507137] RSP: 002b:00007fff9f2e3598 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 [ 556.508637] RAX: 0000000000000000 RBX: 0000000000ebd030 RCX: 00007f8028b77487 [ 556.510069] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000ec41e0 [ 556.511481] RBP: 0000000000ec41e0 R08: 0000000000000000 R09: 0000000000000014 [ 556.512892] R10: 00000000000006b2 R11: 0000000000000246 R12: 00007f802908083c [ 556.514320] R13: 0000000000000000 R14: 0000000000ebd210 R15: 00007fff9f2e3820 [ 556.515745] Modules linked in: snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hwdep snd_hda_core snd_pcm snd_timer snd mac_hid i2c_piix4 soundcore ib_iser rdma_cm iw_cm ib_cm ib_core iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx raid1 raid0 multipath linear 8139too crct10dif_pclmul crc32_pclmul qxl drm_kms_helper syscopyarea aesni_intel sysfillrect sysimgblt fb_sys_fops ttm drm aes_x86_64 crypto_simd cryptd 8139cp glue_helper mii pata_acpi floppy [ 556.529276] ---[ end trace 4ce02f25ff7d3df5 ]--- [ 556.530340] RIP: 0010:f2fs_truncate_inode_blocks+0x4a7/0x6f0 [ 556.531513] Code: e8 ae ea ff ff 41 89 c7 c1 e8 1f 84 c0 74 0a 41 83 ff fe 0f 85 35 ff ff ff 81 85 b0 fe ff ff fb 03 00 00 e9 f7 fd ff ff 0f 0b <0f> 0b e8 62 b7 9a 00 48 8b bd a0 fe ff ff e8 56 54 ae ff 48 8b b5 [ 556.535330] RSP: 0018:ffff8801f292f808 EFLAGS: 00010286 [ 556.536395] RAX: ffffed003e73242d RBX: ffff8801f292f958 RCX: ffffffffb88b81bc [ 556.537824] RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff8801f3992164 [ 556.539290] RBP: ffff8801f292f980 R08: ffffed003e73242d R09: ffffed003e73242d [ 556.540709] R10: 0000000000000001 R11: ffffed003e73242c R12: 00000000fffffc64 [ 556.542131] R13: ffff8801f3992000 R14: 0000000000000058 R15: 00000000ffff8801 [ 556.543579] FS: 00007f8029297840(0000) GS:ffff8801f6f00000(0000) knlGS:0000000000000000 [ 556.545180] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 556.546338] CR2: 000055f5f57305d8 CR3: 00000001f18b0000 CR4: 00000000000006e0 [ 556.547809] ================================================================== [ 556.549248] BUG: KASAN: stack-out-of-bounds in arch_tlb_gather_mmu+0x52/0x170 [ 556.550672] Write of size 8 at addr ffff8801f292fd10 by task umount/1310 [ 556.552338] CPU: 1 PID: 1310 Comm: umount Tainted: G D 4.18.0-rc1+ #4 [ 556.553886] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 [ 556.555756] Call Trace: [ 556.556264] dump_stack+0x7b/0xb5 [ 556.556944] print_address_description+0x70/0x290 [ 556.557903] kasan_report+0x291/0x390 [ 556.558649] ? arch_tlb_gather_mmu+0x52/0x170 [ 556.559537] __asan_store8+0x57/0x90 [ 556.560268] arch_tlb_gather_mmu+0x52/0x170 [ 556.561110] tlb_gather_mmu+0x12/0x40 [ 556.561862] exit_mmap+0x123/0x2a0 [ 556.562555] ? __ia32_sys_munmap+0x50/0x50 [ 556.563384] ? exit_aio+0x98/0x230 [ 556.564079] ? __x32_compat_sys_io_submit+0x260/0x260 [ 556.565099] ? taskstats_exit+0x1f4/0x640 [ 556.565925] ? kasan_check_read+0x11/0x20 [ 556.566739] ? mm_update_next_owner+0x322/0x380 [ 556.567652] mmput+0x8b/0x1d0 [ 556.568260] do_exit+0x43a/0x1390 [ 556.568937] ? mm_update_next_owner+0x380/0x380 [ 556.569855] ? deactivate_super+0x5e/0x80 [ 556.570668] ? cleanup_mnt+0x61/0xa0 [ 556.571395] ? __cleanup_mnt+0x12/0x20 [ 556.572156] ? task_work_run+0xc8/0xf0 [ 556.572917] ? exit_to_usermode_loop+0x125/0x130 [ 556.573861] rewind_stack_do_exit+0x17/0x20 [ 556.574707] RIP: 0033:0x7f8028b77487 [ 556.575428] Code: Bad RIP value. [ 556.576106] RSP: 002b:00007fff9f2e3598 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 [ 556.577599] RAX: 0000000000000000 RBX: 0000000000ebd030 RCX: 00007f8028b77487 [ 556.579020] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000ec41e0 [ 556.580422] RBP: 0000000000ec41e0 R08: 0000000000000000 R09: 0000000000000014 [ 556.581833] R10: 00000000000006b2 R11: 0000000000000246 R12: 00007f802908083c [ 556.583252] R13: 0000000000000000 R14: 0000000000ebd210 R15: 00007fff9f2e3820 [ 556.584983] The buggy address belongs to the page: [ 556.585961] page:ffffea0007ca4bc0 count:0 mapcount:0 mapping:0000000000000000 index:0x0 [ 556.587540] flags: 0x2ffff0000000000() [ 556.588296] raw: 02ffff0000000000 0000000000000000 dead000000000200 0000000000000000 [ 556.589822] raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 [ 556.591359] page dumped because: kasan: bad access detected [ 556.592786] Memory state around the buggy address: [ 556.593753] ffff8801f292fc00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 556.595191] ffff8801f292fc80: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 00 00 00 [ 556.596613] >ffff8801f292fd00: 00 00 f3 00 00 00 00 f3 f3 00 00 00 00 f4 f4 f4 [ 556.598044] ^ [ 556.598797] ffff8801f292fd80: f3 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00 [ 556.600225] ffff8801f292fe00: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 f4 f4 f4 [ 556.601647] ================================================================== - Location https://elixir.bootlin.com/linux/v4.18-rc1/source/fs/f2fs/node.c#L987 case NODE_DIND_BLOCK: err = truncate_nodes(&dn, nofs, offset[1], 3); cont = 0; break; default: BUG(); <--- } Reported-by Wen Xu <wen.xu@gatech.edu> Signed-off-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch add to do sanity check with below field: - cp_pack_total_block_count - blkaddr of data/node - extent info - Overview BUG() in verify_block_addr() when writing to a corrupted f2fs image - Reproduce (4.18 upstream kernel) - POC (poc.c) static void activity(char *mpoint) { char *foo_bar_baz; int err; static int buf[8192]; memset(buf, 0, sizeof(buf)); err = asprintf(&foo_bar_baz, "%s/foo/bar/baz", mpoint); int fd = open(foo_bar_baz, O_RDWR | O_TRUNC, 0777); if (fd >= 0) { write(fd, (char *)buf, sizeof(buf)); fdatasync(fd); close(fd); } } int main(int argc, char *argv[]) { activity(argv[1]); return 0; } - Kernel message [ 689.349473] F2FS-fs (loop0): Mounted with checkpoint version = 3 [ 699.728662] WARNING: CPU: 0 PID: 1309 at fs/f2fs/segment.c:2860 f2fs_inplace_write_data+0x232/0x240 [ 699.728670] Modules linked in: snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hwdep snd_hda_core snd_pcm snd_timer snd mac_hid i2c_piix4 soundcore ib_iser rdma_cm iw_cm ib_cm ib_core iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx raid1 raid0 multipath linear 8139too crct10dif_pclmul crc32_pclmul qxl drm_kms_helper syscopyarea aesni_intel sysfillrect sysimgblt fb_sys_fops ttm drm aes_x86_64 crypto_simd cryptd 8139cp glue_helper mii pata_acpi floppy [ 699.729056] CPU: 0 PID: 1309 Comm: a.out Not tainted 4.18.0-rc1+ #4 [ 699.729064] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 [ 699.729074] RIP: 0010:f2fs_inplace_write_data+0x232/0x240 [ 699.729076] Code: ff e9 cf fe ff ff 49 8d 7d 10 e8 39 45 ad ff 4d 8b 7d 10 be 04 00 00 00 49 8d 7f 48 e8 07 49 ad ff 45 8b 7f 48 e9 fb fe ff ff <0f> 0b f0 41 80 4d 48 04 e9 65 fe ff ff 90 66 66 66 66 90 55 48 8d [ 699.729130] RSP: 0018:ffff8801f43af568 EFLAGS: 00010202 [ 699.729139] RAX: 000000000000003f RBX: ffff8801f43af7b8 RCX: ffffffffb88c9113 [ 699.729142] RDX: 0000000000000003 RSI: dffffc0000000000 RDI: ffff8802024e5540 [ 699.729144] RBP: ffff8801f43af590 R08: 0000000000000009 R09: ffffffffffffffe8 [ 699.729147] R10: 0000000000000001 R11: ffffed0039b0596a R12: ffff8802024e5540 [ 699.729149] R13: ffff8801f0335500 R14: ffff8801e3e7a700 R15: ffff8801e1ee4450 [ 699.729154] FS: 00007f9bf97f5700(0000) GS:ffff8801f6e00000(0000) knlGS:0000000000000000 [ 699.729156] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 699.729159] CR2: 00007f9bf925d170 CR3: 00000001f0c34000 CR4: 00000000000006f0 [ 699.729171] Call Trace: [ 699.729192] f2fs_do_write_data_page+0x2e2/0xe00 [ 699.729203] ? f2fs_should_update_outplace+0xd0/0xd0 [ 699.729238] ? memcg_drain_all_list_lrus+0x280/0x280 [ 699.729269] ? __radix_tree_replace+0xa3/0x120 [ 699.729276] __write_data_page+0x5c7/0xe30 [ 699.729291] ? kasan_check_read+0x11/0x20 [ 699.729310] ? page_mapped+0x8a/0x110 [ 699.729321] ? page_mkclean+0xe9/0x160 [ 699.729327] ? f2fs_do_write_data_page+0xe00/0xe00 [ 699.729331] ? invalid_page_referenced_vma+0x130/0x130 [ 699.729345] ? clear_page_dirty_for_io+0x332/0x450 [ 699.729351] f2fs_write_cache_pages+0x4ca/0x860 [ 699.729358] ? __write_data_page+0xe30/0xe30 [ 699.729374] ? percpu_counter_add_batch+0x22/0xa0 [ 699.729380] ? kasan_check_write+0x14/0x20 [ 699.729391] ? _raw_spin_lock+0x17/0x40 [ 699.729403] ? f2fs_mark_inode_dirty_sync.part.18+0x16/0x30 [ 699.729413] ? iov_iter_advance+0x113/0x640 [ 699.729418] ? f2fs_write_end+0x133/0x2e0 [ 699.729423] ? balance_dirty_pages_ratelimited+0x239/0x640 [ 699.729428] f2fs_write_data_pages+0x329/0x520 [ 699.729433] ? generic_perform_write+0x250/0x320 [ 699.729438] ? f2fs_write_cache_pages+0x860/0x860 [ 699.729454] ? current_time+0x110/0x110 [ 699.729459] ? f2fs_preallocate_blocks+0x1ef/0x370 [ 699.729464] do_writepages+0x37/0xb0 [ 699.729468] ? f2fs_write_cache_pages+0x860/0x860 [ 699.729472] ? do_writepages+0x37/0xb0 [ 699.729478] __filemap_fdatawrite_range+0x19a/0x1f0 [ 699.729483] ? delete_from_page_cache_batch+0x4e0/0x4e0 [ 699.729496] ? __vfs_write+0x2b2/0x410 [ 699.729501] file_write_and_wait_range+0x66/0xb0 [ 699.729506] f2fs_do_sync_file+0x1f9/0xd90 [ 699.729511] ? truncate_partial_data_page+0x290/0x290 [ 699.729521] ? __sb_end_write+0x30/0x50 [ 699.729526] ? vfs_write+0x20f/0x260 [ 699.729530] f2fs_sync_file+0x9a/0xb0 [ 699.729534] ? f2fs_do_sync_file+0xd90/0xd90 [ 699.729548] vfs_fsync_range+0x68/0x100 [ 699.729554] ? __fget_light+0xc9/0xe0 [ 699.729558] do_fsync+0x3d/0x70 [ 699.729562] __x64_sys_fdatasync+0x24/0x30 [ 699.729585] do_syscall_64+0x78/0x170 [ 699.729595] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 699.729613] RIP: 0033:0x7f9bf930d800 [ 699.729615] Code: 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 83 3d 49 bf 2c 00 00 75 10 b8 4b 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 be 78 01 00 48 89 04 24 [ 699.729668] RSP: 002b:00007ffee3606c68 EFLAGS: 00000246 ORIG_RAX: 000000000000004b [ 699.729673] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f9bf930d800 [ 699.729675] RDX: 0000000000008000 RSI: 00000000006010a0 RDI: 0000000000000003 [ 699.729678] RBP: 00007ffee3606ca0 R08: 0000000001503010 R09: 0000000000000000 [ 699.729680] R10: 00000000000002e8 R11: 0000000000000246 R12: 0000000000400610 [ 699.729683] R13: 00007ffee3606da0 R14: 0000000000000000 R15: 0000000000000000 [ 699.729687] ---[ end trace 4ce02f25ff7d3df5 ]--- [ 699.729782] ------------[ cut here ]------------ [ 699.729785] kernel BUG at fs/f2fs/segment.h:654! [ 699.731055] invalid opcode: 0000 [#1] SMP KASAN PTI [ 699.732104] CPU: 0 PID: 1309 Comm: a.out Tainted: G W 4.18.0-rc1+ #4 [ 699.733684] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 [ 699.735611] RIP: 0010:f2fs_submit_page_bio+0x29b/0x730 [ 699.736649] Code: 54 49 8d bd 18 04 00 00 e8 b2 59 af ff 41 8b 8d 18 04 00 00 8b 45 b8 41 d3 e6 44 01 f0 4c 8d 73 14 41 39 c7 0f 82 37 fe ff ff <0f> 0b 65 8b 05 2c 04 77 47 89 c0 48 0f a3 05 52 c1 d5 01 0f 92 c0 [ 699.740524] RSP: 0018:ffff8801f43af508 EFLAGS: 00010283 [ 699.741573] RAX: 0000000000000000 RBX: ffff8801f43af7b8 RCX: ffffffffb88a7cef [ 699.743006] RDX: 0000000000000007 RSI: dffffc0000000000 RDI: ffff8801e3e7a64c [ 699.744426] RBP: ffff8801f43af558 R08: ffffed003e066b55 R09: ffffed003e066b55 [ 699.745833] R10: 0000000000000001 R11: ffffed003e066b54 R12: ffffea0007876940 [ 699.747256] R13: ffff8801f0335500 R14: ffff8801e3e7a600 R15: 0000000000000001 [ 699.748683] FS: 00007f9bf97f5700(0000) GS:ffff8801f6e00000(0000) knlGS:0000000000000000 [ 699.750293] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 699.751462] CR2: 00007f9bf925d170 CR3: 00000001f0c34000 CR4: 00000000000006f0 [ 699.752874] Call Trace: [ 699.753386] ? f2fs_inplace_write_data+0x93/0x240 [ 699.754341] f2fs_inplace_write_data+0xd2/0x240 [ 699.755271] f2fs_do_write_data_page+0x2e2/0xe00 [ 699.756214] ? f2fs_should_update_outplace+0xd0/0xd0 [ 699.757215] ? memcg_drain_all_list_lrus+0x280/0x280 [ 699.758209] ? __radix_tree_replace+0xa3/0x120 [ 699.759164] __write_data_page+0x5c7/0xe30 [ 699.760002] ? kasan_check_read+0x11/0x20 [ 699.760823] ? page_mapped+0x8a/0x110 [ 699.761573] ? page_mkclean+0xe9/0x160 [ 699.762345] ? f2fs_do_write_data_page+0xe00/0xe00 [ 699.763332] ? invalid_page_referenced_vma+0x130/0x130 [ 699.764374] ? clear_page_dirty_for_io+0x332/0x450 [ 699.765347] f2fs_write_cache_pages+0x4ca/0x860 [ 699.766276] ? __write_data_page+0xe30/0xe30 [ 699.767161] ? percpu_counter_add_batch+0x22/0xa0 [ 699.768112] ? kasan_check_write+0x14/0x20 [ 699.768951] ? _raw_spin_lock+0x17/0x40 [ 699.769739] ? f2fs_mark_inode_dirty_sync.part.18+0x16/0x30 [ 699.770885] ? iov_iter_advance+0x113/0x640 [ 699.771743] ? f2fs_write_end+0x133/0x2e0 [ 699.772569] ? balance_dirty_pages_ratelimited+0x239/0x640 [ 699.773680] f2fs_write_data_pages+0x329/0x520 [ 699.774603] ? generic_perform_write+0x250/0x320 [ 699.775544] ? f2fs_write_cache_pages+0x860/0x860 [ 699.776510] ? current_time+0x110/0x110 [ 699.777299] ? f2fs_preallocate_blocks+0x1ef/0x370 [ 699.778279] do_writepages+0x37/0xb0 [ 699.779026] ? f2fs_write_cache_pages+0x860/0x860 [ 699.779978] ? do_writepages+0x37/0xb0 [ 699.780755] __filemap_fdatawrite_range+0x19a/0x1f0 [ 699.781746] ? delete_from_page_cache_batch+0x4e0/0x4e0 [ 699.782820] ? __vfs_write+0x2b2/0x410 [ 699.783597] file_write_and_wait_range+0x66/0xb0 [ 699.784540] f2fs_do_sync_file+0x1f9/0xd90 [ 699.785381] ? truncate_partial_data_page+0x290/0x290 [ 699.786415] ? __sb_end_write+0x30/0x50 [ 699.787204] ? vfs_write+0x20f/0x260 [ 699.787941] f2fs_sync_file+0x9a/0xb0 [ 699.788694] ? f2fs_do_sync_file+0xd90/0xd90 [ 699.789572] vfs_fsync_range+0x68/0x100 [ 699.790360] ? __fget_light+0xc9/0xe0 [ 699.791128] do_fsync+0x3d/0x70 [ 699.791779] __x64_sys_fdatasync+0x24/0x30 [ 699.792614] do_syscall_64+0x78/0x170 [ 699.793371] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 699.794406] RIP: 0033:0x7f9bf930d800 [ 699.795134] Code: 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 83 3d 49 bf 2c 00 00 75 10 b8 4b 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 be 78 01 00 48 89 04 24 [ 699.798960] RSP: 002b:00007ffee3606c68 EFLAGS: 00000246 ORIG_RAX: 000000000000004b [ 699.800483] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f9bf930d800 [ 699.801923] RDX: 0000000000008000 RSI: 00000000006010a0 RDI: 0000000000000003 [ 699.803373] RBP: 00007ffee3606ca0 R08: 0000000001503010 R09: 0000000000000000 [ 699.804798] R10: 00000000000002e8 R11: 0000000000000246 R12: 0000000000400610 [ 699.806233] R13: 00007ffee3606da0 R14: 0000000000000000 R15: 0000000000000000 [ 699.807667] Modules linked in: snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hwdep snd_hda_core snd_pcm snd_timer snd mac_hid i2c_piix4 soundcore ib_iser rdma_cm iw_cm ib_cm ib_core iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx raid1 raid0 multipath linear 8139too crct10dif_pclmul crc32_pclmul qxl drm_kms_helper syscopyarea aesni_intel sysfillrect sysimgblt fb_sys_fops ttm drm aes_x86_64 crypto_simd cryptd 8139cp glue_helper mii pata_acpi floppy [ 699.817079] ---[ end trace 4ce02f25ff7d3df6 ]--- [ 699.818068] RIP: 0010:f2fs_submit_page_bio+0x29b/0x730 [ 699.819114] Code: 54 49 8d bd 18 04 00 00 e8 b2 59 af ff 41 8b 8d 18 04 00 00 8b 45 b8 41 d3 e6 44 01 f0 4c 8d 73 14 41 39 c7 0f 82 37 fe ff ff <0f> 0b 65 8b 05 2c 04 77 47 89 c0 48 0f a3 05 52 c1 d5 01 0f 92 c0 [ 699.822919] RSP: 0018:ffff8801f43af508 EFLAGS: 00010283 [ 699.823977] RAX: 0000000000000000 RBX: ffff8801f43af7b8 RCX: ffffffffb88a7cef [ 699.825436] RDX: 0000000000000007 RSI: dffffc0000000000 RDI: ffff8801e3e7a64c [ 699.826881] RBP: ffff8801f43af558 R08: ffffed003e066b55 R09: ffffed003e066b55 [ 699.828292] R10: 0000000000000001 R11: ffffed003e066b54 R12: ffffea0007876940 [ 699.829750] R13: ffff8801f0335500 R14: ffff8801e3e7a600 R15: 0000000000000001 [ 699.831192] FS: 00007f9bf97f5700(0000) GS:ffff8801f6e00000(0000) knlGS:0000000000000000 [ 699.832793] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 699.833981] CR2: 00007f9bf925d170 CR3: 00000001f0c34000 CR4: 00000000000006f0 [ 699.835556] ================================================================== [ 699.837029] BUG: KASAN: stack-out-of-bounds in update_stack_state+0x38c/0x3e0 [ 699.838462] Read of size 8 at addr ffff8801f43af970 by task a.out/1309 [ 699.840086] CPU: 0 PID: 1309 Comm: a.out Tainted: G D W 4.18.0-rc1+ #4 [ 699.841603] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 [ 699.843475] Call Trace: [ 699.843982] dump_stack+0x7b/0xb5 [ 699.844661] print_address_description+0x70/0x290 [ 699.845607] kasan_report+0x291/0x390 [ 699.846351] ? update_stack_state+0x38c/0x3e0 [ 699.853831] __asan_load8+0x54/0x90 [ 699.854569] update_stack_state+0x38c/0x3e0 [ 699.855428] ? __read_once_size_nocheck.constprop.7+0x20/0x20 [ 699.856601] ? __save_stack_trace+0x5e/0x100 [ 699.857476] unwind_next_frame.part.5+0x18e/0x490 [ 699.858448] ? unwind_dump+0x290/0x290 [ 699.859217] ? clear_page_dirty_for_io+0x332/0x450 [ 699.860185] __unwind_start+0x106/0x190 [ 699.860974] __save_stack_trace+0x5e/0x100 [ 699.861808] ? __save_stack_trace+0x5e/0x100 [ 699.862691] ? unlink_anon_vmas+0xba/0x2c0 [ 699.863525] save_stack_trace+0x1f/0x30 [ 699.864312] save_stack+0x46/0xd0 [ 699.864993] ? __alloc_pages_slowpath+0x1420/0x1420 [ 699.865990] ? flush_tlb_mm_range+0x15e/0x220 [ 699.866889] ? kasan_check_write+0x14/0x20 [ 699.867724] ? __dec_node_state+0x92/0xb0 [ 699.868543] ? lock_page_memcg+0x85/0xf0 [ 699.869350] ? unlock_page_memcg+0x16/0x80 [ 699.870185] ? page_remove_rmap+0x198/0x520 [ 699.871048] ? mark_page_accessed+0x133/0x200 [ 699.871930] ? _cond_resched+0x1a/0x50 [ 699.872700] ? unmap_page_range+0xcd4/0xe50 [ 699.873551] ? rb_next+0x58/0x80 [ 699.874217] ? rb_next+0x58/0x80 [ 699.874895] __kasan_slab_free+0x13c/0x1a0 [ 699.875734] ? unlink_anon_vmas+0xba/0x2c0 [ 699.876563] kasan_slab_free+0xe/0x10 [ 699.877315] kmem_cache_free+0x89/0x1e0 [ 699.878095] unlink_anon_vmas+0xba/0x2c0 [ 699.878913] free_pgtables+0x101/0x1b0 [ 699.879677] exit_mmap+0x146/0x2a0 [ 699.880378] ? __ia32_sys_munmap+0x50/0x50 [ 699.881214] ? kasan_check_read+0x11/0x20 [ 699.882052] ? mm_update_next_owner+0x322/0x380 [ 699.882985] mmput+0x8b/0x1d0 [ 699.883602] do_exit+0x43a/0x1390 [ 699.884288] ? mm_update_next_owner+0x380/0x380 [ 699.885212] ? f2fs_sync_file+0x9a/0xb0 [ 699.885995] ? f2fs_do_sync_file+0xd90/0xd90 [ 699.886877] ? vfs_fsync_range+0x68/0x100 [ 699.887694] ? __fget_light+0xc9/0xe0 [ 699.888442] ? do_fsync+0x3d/0x70 [ 699.889118] ? __x64_sys_fdatasync+0x24/0x30 [ 699.889996] rewind_stack_do_exit+0x17/0x20 [ 699.890860] RIP: 0033:0x7f9bf930d800 [ 699.891585] Code: Bad RIP value. [ 699.892268] RSP: 002b:00007ffee3606c68 EFLAGS: 00000246 ORIG_RAX: 000000000000004b [ 699.893781] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f9bf930d800 [ 699.895220] RDX: 0000000000008000 RSI: 00000000006010a0 RDI: 0000000000000003 [ 699.896643] RBP: 00007ffee3606ca0 R08: 0000000001503010 R09: 0000000000000000 [ 699.898069] R10: 00000000000002e8 R11: 0000000000000246 R12: 0000000000400610 [ 699.899505] R13: 00007ffee3606da0 R14: 0000000000000000 R15: 0000000000000000 [ 699.901241] The buggy address belongs to the page: [ 699.902215] page:ffffea0007d0ebc0 count:0 mapcount:0 mapping:0000000000000000 index:0x0 [ 699.903811] flags: 0x2ffff0000000000() [ 699.904585] raw: 02ffff0000000000 0000000000000000 ffffffff07d00101 0000000000000000 [ 699.906125] raw: 0000000000000000 0000000000240000 00000000ffffffff 0000000000000000 [ 699.907673] page dumped because: kasan: bad access detected [ 699.909108] Memory state around the buggy address: [ 699.910077] ffff8801f43af800: 00 f1 f1 f1 f1 00 f4 f4 f4 f3 f3 f3 f3 00 00 00 [ 699.911528] ffff8801f43af880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 699.912953] >ffff8801f43af900: 00 00 00 00 00 00 00 00 f1 01 f4 f4 f4 f2 f2 f2 [ 699.914392] ^ [ 699.915758] ffff8801f43af980: f2 00 f4 f4 00 00 00 00 f2 00 00 00 00 00 00 00 [ 699.917193] ffff8801f43afa00: 00 00 00 00 00 00 00 00 00 f3 f3 f3 00 00 00 00 [ 699.918634] ================================================================== - Location https://elixir.bootlin.com/linux/v4.18-rc1/source/fs/f2fs/segment.h#L644 Reported-by Wen Xu <wen.xu@gatech.edu> Signed-off-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

https://bugzilla.kernel.org/show_bug.cgi?id=200221 - Overview BUG() in clear_inode() when mounting and un-mounting a corrupted f2fs image - Reproduce - Kernel message [ 538.601448] F2FS-fs (loop0): Invalid segment/section count (31, 24 x 1376257) [ 538.601458] F2FS-fs (loop0): Can't find valid F2FS filesystem in 2th superblock [ 538.724091] F2FS-fs (loop0): Try to recover 2th superblock, ret: 0 [ 538.724102] F2FS-fs (loop0): Mounted with checkpoint version = 2 [ 540.970834] ------------[ cut here ]------------ [ 540.970838] kernel BUG at fs/inode.c:512! [ 540.971750] invalid opcode: 0000 [#1] SMP KASAN PTI [ 540.972755] CPU: 1 PID: 1305 Comm: umount Not tainted 4.18.0-rc1+ #4 [ 540.974034] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 [ 540.982913] RIP: 0010:clear_inode+0xc0/0xd0 [ 540.983774] Code: 8d a3 30 01 00 00 4c 89 e7 e8 1c ec f8 ff 48 8b 83 30 01 00 00 49 39 c4 75 1a 48 c7 83 a0 00 00 00 60 00 00 00 5b 41 5c 5d c3 <0f> 0b 0f 0b 0f 0b 0f 0b 0f 0b 0f 0b 0f 1f 40 00 66 66 66 66 90 55 [ 540.987570] RSP: 0018:ffff8801e34a7b70 EFLAGS: 00010002 [ 540.988636] RAX: 0000000000000000 RBX: ffff8801e9b744e8 RCX: ffffffffb840eb3a [ 540.990063] RDX: dffffc0000000000 RSI: 0000000000000004 RDI: ffff8801e9b746b8 [ 540.991499] RBP: ffff8801e34a7b80 R08: ffffed003d36e8ce R09: ffffed003d36e8ce [ 540.992923] R10: 0000000000000001 R11: ffffed003d36e8cd R12: ffff8801e9b74668 [ 540.994360] R13: ffff8801e9b74760 R14: ffff8801e9b74528 R15: ffff8801e9b74530 [ 540.995786] FS: 00007f4662bdf840(0000) GS:ffff8801f6f00000(0000) knlGS:0000000000000000 [ 540.997403] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 540.998571] CR2: 000000000175c568 CR3: 00000001dcfe6000 CR4: 00000000000006e0 [ 541.000015] Call Trace: [ 541.000554] f2fs_evict_inode+0x253/0x630 [ 541.001381] evict+0x16f/0x290 [ 541.002015] iput+0x280/0x300 [ 541.002654] dentry_unlink_inode+0x165/0x1e0 [ 541.003528] __dentry_kill+0x16a/0x260 [ 541.004300] dentry_kill+0x70/0x250 [ 541.005018] dput+0x154/0x1d0 [ 541.005635] do_one_tree+0x34/0x40 [ 541.006354] shrink_dcache_for_umount+0x3f/0xa0 [ 541.007285] generic_shutdown_super+0x43/0x1c0 [ 541.008192] kill_block_super+0x52/0x80 [ 541.008978] kill_f2fs_super+0x62/0x70 [ 541.009750] deactivate_locked_super+0x6f/0xa0 [ 541.010664] deactivate_super+0x5e/0x80 [ 541.011450] cleanup_mnt+0x61/0xa0 [ 541.012151] __cleanup_mnt+0x12/0x20 [ 541.012893] task_work_run+0xc8/0xf0 [ 541.013635] exit_to_usermode_loop+0x125/0x130 [ 541.014555] do_syscall_64+0x138/0x170 [ 541.015340] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 541.016375] RIP: 0033:0x7f46624bf487 [ 541.017104] Code: 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e1 c9 2b 00 f7 d8 64 89 01 48 [ 541.020923] RSP: 002b:00007fff5e12e9a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 [ 541.022452] RAX: 0000000000000000 RBX: 0000000001753030 RCX: 00007f46624bf487 [ 541.023885] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 000000000175a1e0 [ 541.025318] RBP: 000000000175a1e0 R08: 0000000000000000 R09: 0000000000000014 [ 541.026755] R10: 00000000000006b2 R11: 0000000000000246 R12: 00007f46629c883c [ 541.028186] R13: 0000000000000000 R14: 0000000001753210 R15: 00007fff5e12ec30 [ 541.029626] Modules linked in: snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hwdep snd_hda_core snd_pcm snd_timer snd mac_hid i2c_piix4 soundcore ib_iser rdma_cm iw_cm ib_cm ib_core iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx raid1 raid0 multipath linear 8139too crct10dif_pclmul crc32_pclmul qxl drm_kms_helper syscopyarea aesni_intel sysfillrect sysimgblt fb_sys_fops ttm drm aes_x86_64 crypto_simd cryptd 8139cp glue_helper mii pata_acpi floppy [ 541.039445] ---[ end trace 4ce02f25ff7d3df5 ]--- [ 541.040392] RIP: 0010:clear_inode+0xc0/0xd0 [ 541.041240] Code: 8d a3 30 01 00 00 4c 89 e7 e8 1c ec f8 ff 48 8b 83 30 01 00 00 49 39 c4 75 1a 48 c7 83 a0 00 00 00 60 00 00 00 5b 41 5c 5d c3 <0f> 0b 0f 0b 0f 0b 0f 0b 0f 0b 0f 0b 0f 1f 40 00 66 66 66 66 90 55 [ 541.045042] RSP: 0018:ffff8801e34a7b70 EFLAGS: 00010002 [ 541.046099] RAX: 0000000000000000 RBX: ffff8801e9b744e8 RCX: ffffffffb840eb3a [ 541.047537] RDX: dffffc0000000000 RSI: 0000000000000004 RDI: ffff8801e9b746b8 [ 541.048965] RBP: ffff8801e34a7b80 R08: ffffed003d36e8ce R09: ffffed003d36e8ce [ 541.050402] R10: 0000000000000001 R11: ffffed003d36e8cd R12: ffff8801e9b74668 [ 541.051832] R13: ffff8801e9b74760 R14: ffff8801e9b74528 R15: ffff8801e9b74530 [ 541.053263] FS: 00007f4662bdf840(0000) GS:ffff8801f6f00000(0000) knlGS:0000000000000000 [ 541.054891] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 541.056039] CR2: 000000000175c568 CR3: 00000001dcfe6000 CR4: 00000000000006e0 [ 541.058506] ================================================================== [ 541.059991] BUG: KASAN: stack-out-of-bounds in update_stack_state+0x38c/0x3e0 [ 541.061513] Read of size 8 at addr ffff8801e34a7970 by task umount/1305 [ 541.063302] CPU: 1 PID: 1305 Comm: umount Tainted: G D 4.18.0-rc1+ #4 [ 541.064838] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 [ 541.066778] Call Trace: [ 541.067294] dump_stack+0x7b/0xb5 [ 541.067986] print_address_description+0x70/0x290 [ 541.068941] kasan_report+0x291/0x390 [ 541.069692] ? update_stack_state+0x38c/0x3e0 [ 541.070598] __asan_load8+0x54/0x90 [ 541.071315] update_stack_state+0x38c/0x3e0 [ 541.072172] ? __read_once_size_nocheck.constprop.7+0x20/0x20 [ 541.073340] ? vprintk_func+0x27/0x60 [ 541.074096] ? printk+0xa3/0xd3 [ 541.074762] ? __save_stack_trace+0x5e/0x100 [ 541.075634] unwind_next_frame.part.5+0x18e/0x490 [ 541.076594] ? unwind_dump+0x290/0x290 [ 541.077368] ? __show_regs+0x2c4/0x330 [ 541.078142] __unwind_start+0x106/0x190 [ 541.085422] __save_stack_trace+0x5e/0x100 [ 541.086268] ? __save_stack_trace+0x5e/0x100 [ 541.087161] ? unlink_anon_vmas+0xba/0x2c0 [ 541.087997] save_stack_trace+0x1f/0x30 [ 541.088782] save_stack+0x46/0xd0 [ 541.089475] ? __alloc_pages_slowpath+0x1420/0x1420 [ 541.090477] ? flush_tlb_mm_range+0x15e/0x220 [ 541.091364] ? __dec_node_state+0x24/0xb0 [ 541.092180] ? lock_page_memcg+0x85/0xf0 [ 541.092979] ? unlock_page_memcg+0x16/0x80 [ 541.093812] ? page_remove_rmap+0x198/0x520 [ 541.094674] ? mark_page_accessed+0x133/0x200 [ 541.095559] ? _cond_resched+0x1a/0x50 [ 541.096326] ? unmap_page_range+0xcd4/0xe50 [ 541.097179] ? rb_next+0x58/0x80 [ 541.097845] ? rb_next+0x58/0x80 [ 541.098518] __kasan_slab_free+0x13c/0x1a0 [ 541.099352] ? unlink_anon_vmas+0xba/0x2c0 [ 541.100184] kasan_slab_free+0xe/0x10 [ 541.100934] kmem_cache_free+0x89/0x1e0 [ 541.101724] unlink_anon_vmas+0xba/0x2c0 [ 541.102534] free_pgtables+0x101/0x1b0 [ 541.103299] exit_mmap+0x146/0x2a0 [ 541.103996] ? __ia32_sys_munmap+0x50/0x50 [ 541.104829] ? kasan_check_read+0x11/0x20 [ 541.105649] ? mm_update_next_owner+0x322/0x380 [ 541.106578] mmput+0x8b/0x1d0 [ 541.107191] do_exit+0x43a/0x1390 [ 541.107876] ? mm_update_next_owner+0x380/0x380 [ 541.108791] ? deactivate_super+0x5e/0x80 [ 541.109610] ? cleanup_mnt+0x61/0xa0 [ 541.110351] ? __cleanup_mnt+0x12/0x20 [ 541.111115] ? task_work_run+0xc8/0xf0 [ 541.111879] ? exit_to_usermode_loop+0x125/0x130 [ 541.112817] rewind_stack_do_exit+0x17/0x20 [ 541.113666] RIP: 0033:0x7f46624bf487 [ 541.114404] Code: Bad RIP value. [ 541.115094] RSP: 002b:00007fff5e12e9a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 [ 541.116605] RAX: 0000000000000000 RBX: 0000000001753030 RCX: 00007f46624bf487 [ 541.118034] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 000000000175a1e0 [ 541.119472] RBP: 000000000175a1e0 R08: 0000000000000000 R09: 0000000000000014 [ 541.120890] R10: 00000000000006b2 R11: 0000000000000246 R12: 00007f46629c883c [ 541.122321] R13: 0000000000000000 R14: 0000000001753210 R15: 00007fff5e12ec30 [ 541.124061] The buggy address belongs to the page: [ 541.125042] page:ffffea00078d29c0 count:0 mapcount:0 mapping:0000000000000000 index:0x0 [ 541.126651] flags: 0x2ffff0000000000() [ 541.127418] raw: 02ffff0000000000 dead000000000100 dead000000000200 0000000000000000 [ 541.128963] raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 [ 541.130516] page dumped because: kasan: bad access detected [ 541.131954] Memory state around the buggy address: [ 541.132924] ffff8801e34a7800: 00 f1 f1 f1 f1 00 f4 f4 f4 f3 f3 f3 f3 00 00 00 [ 541.134378] ffff8801e34a7880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 541.135814] >ffff8801e34a7900: 00 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 [ 541.137253] ^ [ 541.138637] ffff8801e34a7980: f1 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 541.140075] ffff8801e34a7a00: 00 00 00 00 00 00 00 00 f3 00 00 00 00 00 00 00 [ 541.141509] ================================================================== - Location https://elixir.bootlin.com/linux/v4.18-rc1/source/fs/inode.c#L512 BUG_ON(inode->i_data.nrpages); The root cause is root directory inode is corrupted, it has both inline_data and inline_dentry flag, and its nlink is zero, so in ->evict(), after dropping all page cache, it grabs page #0 for inline data truncation, result in panic in later clear_inode() where we will check inode->i_data.nrpages value. This patch adds inline flags check in sanity_check_inode, in addition, do sanity check with root inode's nlink. Reported-by Wen Xu <wen.xu@gatech.edu> Signed-off-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Currently, whenever a new node is created/re-used from the memhotplug path, we call free_area_init_node()->free_area_init_core(). But there is some code that we do not really need to run when we are coming from such path. free_area_init_core() performs the following actions: 1) Initializes pgdat internals, such as spinlock, waitqueues and more. 2) Account # nr_all_pages and # nr_kernel_pages. These values are used later on when creating hash tables. 3) Account number of managed_pages per zone, substracting dma_reserved and memmap pages. 4) Initializes some fields of the zone structure data 5) Calls init_currently_empty_zone to initialize all the freelists 6) Calls memmap_init to initialize all pages belonging to certain zone When called from memhotplug path, free_area_init_core() only performs actions #1 and #4. Action #2 is pointless as the zones do not have any pages since either the node was freed, or we are re-using it, eitherway all zones belonging to this node should have 0 pages. For the same reason, action #3 results always in manages_pages being 0. Action #5 and #6 are performed later on when onlining the pages: online_pages()->move_pfn_range_to_zone()->init_currently_empty_zone() online_pages()->move_pfn_range_to_zone()->memmap_init_zone() This patch does two things: First, moves the node/zone initializtion to their own function, so it allows us to create a small version of free_area_init_core, where we only perform: 1) Initialization of pgdat internals, such as spinlock, waitqueues and more 4) Initialization of some fields of the zone structure data These two functions are: pgdat_init_internals() and zone_init_internals(). The second thing this patch does, is to introduce free_area_init_core_hotplug(), the memhotplug version of free_area_init_core(): Currently, we call free_area_init_node() from the memhotplug path. In there, we set some pgdat's fields, and call calculate_node_totalpages(). calculate_node_totalpages() calculates the # of pages the node has. Since the node is either new, or we are re-using it, the zones belonging to this node should not have any pages, so there is no point to calculate this now. Actually, we re-set these values to 0 later on with the calls to: reset_node_managed_pages() reset_node_present_pages() The # of pages per node and the # of pages per zone will be calculated when onlining the pages: online_pages()->move_pfn_range()->move_pfn_range_to_zone()->resize_zone_range() online_pages()->move_pfn_range()->move_pfn_range_to_zone()->resize_pgdat_range() Also, since free_area_init_core/free_area_init_node will now only get called during early init, let us replace __paginginit with __init, so their code gets freed up. [osalvador@techadventures.net: fix section usage] Link: http://lkml.kernel.org/r/20180731101752.GA473@techadventures.net [osalvador@suse.de: v6] Link: http://lkml.kernel.org/r/20180801122348.21588-6-osalvador@techadventures.net Link: http://lkml.kernel.org/r/20180730101757.28058-5-osalvador@techadventures.net Signed-off-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Pavel Tatashin <pasha.tatashin@oracle.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com> Cc: Aaron Lu <aaron.lu@intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Patch series "add support for relative references in special sections", v10. This adds support for emitting special sections such as initcall arrays, PCI fixups and tracepoints as relative references rather than absolute references. This reduces the size by 50% on 64-bit architectures, but more importantly, it removes the need for carrying relocation metadata for these sections in relocatable kernels (e.g., for KASLR) that needs to be fixed up at boot time. On arm64, this reduces the vmlinux footprint of such a reference by 8x (8 byte absolute reference + 24 byte RELA entry vs 4 byte relative reference) Patch #3 was sent out before as a single patch. This series supersedes the previous submission. This version makes relative ksymtab entries dependent on the new Kconfig symbol HAVE_ARCH_PREL32_RELOCATIONS rather than trying to infer from kbuild test robot replies for which architectures it should be blacklisted. Patch #1 introduces the new Kconfig symbol HAVE_ARCH_PREL32_RELOCATIONS, and sets it for the main architectures that are expected to benefit the most from this feature, i.e., 64-bit architectures or ones that use runtime relocations. Patch #2 add support for #define'ing __DISABLE_EXPORTS to get rid of ksymtab/kcrctab sections in decompressor and EFI stub objects when rebuilding existing C files to run in a different context. Patches #4 - #6 implement relative references for initcalls, PCI fixups and tracepoints, respectively, all of which produce sections with order ~1000 entries on an arm64 defconfig kernel with tracing enabled. This means we save about 28 KB of vmlinux space for each of these patches. [From the v7 series blurb, which included the jump_label patches as well]: For the arm64 kernel, all patches combined reduce the memory footprint of vmlinux by about 1.3 MB (using a config copied from Ubuntu that has KASLR enabled), of which ~1 MB is the size reduction of the RELA section in .init, and the remaining 300 KB is reduction of .text/.data. This patch (of 6): Before updating certain subsystems to use place relative 32-bit relocations in special sections, to save space and reduce the number of absolute relocations that need to be processed at runtime by relocatable kernels, introduce the Kconfig symbol and define it for some architectures that should be able to support and benefit from it. Link: http://lkml.kernel.org/r/20180704083651.24360-2-ard.biesheuvel@linaro.org Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Will Deacon <will.deacon@arm.com> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Kees Cook <keescook@chromium.org> Cc: Thomas Garnier <thgarnie@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Paul Mackerras <paulus@samba.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Petr Mladek <pmladek@suse.com> Cc: James Morris <jmorris@namei.org> Cc: Nicolas Pitre <nico@linaro.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>, Cc: James Morris <james.morris@microsoft.com> Cc: Jessica Yu <jeyu@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The writeback thread would exit with a lock held when the cache device is detached via sysfs interface, fix it by releasing the held lock before exiting the while-loop. Fixes: fadd94e (bcache: quit dc->writeback_thread when BCACHE_DEV_DETACHING is set) Signed-off-by: Shan Hai <shan.hai@oracle.com> Signed-off-by: Coly Li <colyli@suse.de> Tested-by: Shenghui Wang <shhuiw@foxmail.com> Cc: stable@vger.kernel.org #4.17+ Signed-off-by: Jens Axboe <axboe@kernel.dk>

I changed the way mac80211 updates the PM state of the peer. I forgot that we could also have multicast frames from the peer and that those frame should of course not change the PM state of the peer: A peer goes to power save when it needs to scan, but it won't send the broadcast Probe Request with the PM bit set. This made us mark the peer as awake when it wasn't and then Intel's firmware would fail to transmit because the peer is asleep according to its database. The driver warned about this and it looked like this: WARNING: CPU: 0 PID: 184 at /usr/src/linux-4.16.14/drivers/net/wireless/intel/iwlwifi/mvm/tx.c:1369 iwl_mvm_rx_tx_cmd+0x53b/0x860 CPU: 0 PID: 184 Comm: irq/124-iwlwifi Not tainted 4.16.14 #1 RIP: 0010:iwl_mvm_rx_tx_cmd+0x53b/0x860 Call Trace: iwl_pcie_rx_handle+0x220/0x880 iwl_pcie_irq_handler+0x6c9/0xa20 ? irq_forced_thread_fn+0x60/0x60 ? irq_thread_dtor+0x90/0x90 The relevant code that spits the WARNING is: case TX_STATUS_FAIL_DEST_PS: /* the FW should have stopped the queue and not * return this status */ WARN_ON(1); info->flags |= IEEE80211_TX_STAT_TX_FILTERED; This fixes https://bugzilla.kernel.org/show_bug.cgi?id=199967. Fixes: 9fef654 ("mac80211: always update the PM state of a peer on MGMT / DATA frames") Cc: <stable@vger.kernel.org> #4.16+ Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com>

apparmor_secid_to_secctx() has a bad debug statement tripping on a condition handle by the code. When kconfig SECURITY_APPARMOR_DEBUG is enabled the debug WARN_ON will trip when **secdata is NULL resulting in the following trace. ------------[ cut here ]------------ AppArmor WARN apparmor_secid_to_secctx: ((!secdata)): WARNING: CPU: 0 PID: 14826 at security/apparmor/secid.c:82 apparmor_secid_to_secctx+0x2b5/0x2f0 security/apparmor/secid.c:82 Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 14826 Comm: syz-executor1 Not tainted 4.19.0-rc1+ #193 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113 panic+0x238/0x4e7 kernel/panic.c:184 __warn.cold.8+0x163/0x1ba kernel/panic.c:536 report_bug+0x252/0x2d0 lib/bug.c:186 fixup_bug arch/x86/kernel/traps.c:178 [inline] do_error_trap+0x1fc/0x4d0 arch/x86/kernel/traps.c:296 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:316 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:993 RIP: 0010:apparmor_secid_to_secctx+0x2b5/0x2f0 security/apparmor/secid.c:82 Code: c7 c7 40 66 58 87 e8 6a 6d 0f fe 0f 0b e9 6c fe ff ff e8 3e aa 44 fe 48 c7 c6 80 67 58 87 48 c7 c7 a0 65 58 87 e8 4b 6d 0f fe <0f> 0b e9 3f fe ff ff 48 89 df e8 fc a7 83 fe e9 ed fe ff ff bb f4 RSP: 0018:ffff8801ba1bed10 EFLAGS: 00010286 RAX: 0000000000000000 RBX: ffff8801ba1beed0 RCX: ffffc9000227e000 RDX: 0000000000018482 RSI: ffffffff8163ac01 RDI: 0000000000000001 RBP: ffff8801ba1bed30 R08: ffff8801b80ec080 R09: ffffed003b603eca R10: ffffed003b603eca R11: ffff8801db01f657 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000000 R15: ffff8801ba1beed0 security_secid_to_secctx+0x63/0xc0 security/security.c:1314 ctnetlink_secctx_size net/netfilter/nf_conntrack_netlink.c:621 [inline] ctnetlink_nlmsg_size net/netfilter/nf_conntrack_netlink.c:659 [inline] ctnetlink_conntrack_event+0x303/0x1470 net/netfilter/nf_conntrack_netlink.c:706 nf_conntrack_eventmask_report+0x55f/0x930 net/netfilter/nf_conntrack_ecache.c:151 nf_conntrack_event_report include/net/netfilter/nf_conntrack_ecache.h:112 [inline] nf_ct_delete+0x33c/0x5d0 net/netfilter/nf_conntrack_core.c:601 nf_ct_iterate_cleanup+0x48c/0x5e0 net/netfilter/nf_conntrack_core.c:1892 nf_ct_iterate_cleanup_net+0x23c/0x2d0 net/netfilter/nf_conntrack_core.c:1974 ctnetlink_flush_conntrack net/netfilter/nf_conntrack_netlink.c:1226 [inline] ctnetlink_del_conntrack+0x66c/0x850 net/netfilter/nf_conntrack_netlink.c:1258 nfnetlink_rcv_msg+0xd88/0x1070 net/netfilter/nfnetlink.c:228 netlink_rcv_skb+0x172/0x440 net/netlink/af_netlink.c:2454 nfnetlink_rcv+0x1c0/0x4d0 net/netfilter/nfnetlink.c:560 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline] netlink_unicast+0x5a0/0x760 net/netlink/af_netlink.c:1343 netlink_sendmsg+0xa18/0xfc0 net/netlink/af_netlink.c:1908 sock_sendmsg_nosec net/socket.c:621 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:631 ___sys_sendmsg+0x7fd/0x930 net/socket.c:2114 __sys_sendmsg+0x11d/0x290 net/socket.c:2152 __do_sys_sendmsg net/socket.c:2161 [inline] __se_sys_sendmsg net/socket.c:2159 [inline] __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2159 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457089 Code: fd b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f7bc6e03c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f7bc6e046d4 RCX: 0000000000457089 RDX: 0000000000000000 RSI: 0000000020d65000 RDI: 0000000000000003 RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d4588 R14: 00000000004c8d5c R15: 0000000000000000 Dumping ftrace buffer: (ftrace buffer empty) Kernel Offset: disabled Rebooting in 86400 seconds.. CC: <stable@vger.kernel.org> #4.18 Fixes: c092921 ("apparmor: add support for mapping secids and using secctxes") Reported-by: syzbot+21016130b0580a9de3b5@syzkaller.appspotmail.com Signed-off-by: John Johansen <john.johansen@canonical.com>

…_values fails Fixes a use-after-free reported by KASAN when later iscsi_target_login_sess_out gets called and it tries to access conn->sess->se_sess: Disabling lock debugging due to kernel taint iSCSI Login timeout on Network Portal [::]:3260 iSCSI Login negotiation failed. ================================================================== BUG: KASAN: use-after-free in iscsi_target_login_sess_out.cold.12+0x58/0xff [iscsi_target_mod] Read of size 8 at addr ffff880109d070c8 by task iscsi_np/980 CPU: 1 PID: 980 Comm: iscsi_np Tainted: G O 4.17.8kasan.sess.connops+ #4 Hardware name: To be filled by O.E.M. To be filled by O.E.M./Aptio CRB, BIOS 5.6.5 05/19/2014 Call Trace: dump_stack+0x71/0xac print_address_description+0x65/0x22e ? iscsi_target_login_sess_out.cold.12+0x58/0xff [iscsi_target_mod] kasan_report.cold.6+0x241/0x2fd iscsi_target_login_sess_out.cold.12+0x58/0xff [iscsi_target_mod] iscsi_target_login_thread+0x1086/0x1710 [iscsi_target_mod] ? __sched_text_start+0x8/0x8 ? iscsi_target_login_sess_out+0x250/0x250 [iscsi_target_mod] ? __kthread_parkme+0xcc/0x100 ? parse_args.cold.14+0xd3/0xd3 ? iscsi_target_login_sess_out+0x250/0x250 [iscsi_target_mod] kthread+0x1a0/0x1c0 ? kthread_bind+0x30/0x30 ret_from_fork+0x35/0x40 Allocated by task 980: kasan_kmalloc+0xbf/0xe0 kmem_cache_alloc_trace+0x112/0x210 iscsi_target_login_thread+0x816/0x1710 [iscsi_target_mod] kthread+0x1a0/0x1c0 ret_from_fork+0x35/0x40 Freed by task 980: __kasan_slab_free+0x125/0x170 kfree+0x90/0x1d0 iscsi_target_login_thread+0x1577/0x1710 [iscsi_target_mod] kthread+0x1a0/0x1c0 ret_from_fork+0x35/0x40 The buggy address belongs to the object at ffff880109d06f00 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 456 bytes inside of 512-byte region [ffff880109d06f00, ffff880109d07100) The buggy address belongs to the page: page:ffffea0004274180 count:1 mapcount:0 mapping:0000000000000000 index:0x0 compound_mapcount: 0 flags: 0x17fffc000008100(slab|head) raw: 017fffc000008100 0000000000000000 0000000000000000 00000001000c000c raw: dead000000000100 dead000000000200 ffff88011b002e00 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff880109d06f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff880109d07000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff880109d07080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff880109d07100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff880109d07180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== Signed-off-by: Vincent Pelletier <plr.vincent@gmail.com> [rebased against idr/ida changes and to handle ret review comments from Matthew] Signed-off-by: Mike Christie <mchristi@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Reviewed-by: Matthew Wilcox <willy@infradead.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

…equests Currently, nouveau uses the generic drm_fb_helper_output_poll_changed() function provided by DRM as it's output_poll_changed callback. Unfortunately however, this function doesn't grab runtime PM references early enough and even if it did-we can't block waiting for the device to resume in output_poll_changed() since it's very likely that we'll need to grab the fb_helper lock at some point during the runtime resume process. This currently results in deadlocking like so: [ 246.669625] INFO: task kworker/4:0:37 blocked for more than 120 seconds. [ 246.673398] Not tainted 4.18.0-rc5Lyude-Test+ #2 [ 246.675271] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 246.676527] kworker/4:0 D 0 37 2 0x80000000 [ 246.677580] Workqueue: events output_poll_execute [drm_kms_helper] [ 246.678704] Call Trace: [ 246.679753] __schedule+0x322/0xaf0 [ 246.680916] schedule+0x33/0x90 [ 246.681924] schedule_preempt_disabled+0x15/0x20 [ 246.683023] __mutex_lock+0x569/0x9a0 [ 246.684035] ? kobject_uevent_env+0x117/0x7b0 [ 246.685132] ? drm_fb_helper_hotplug_event.part.28+0x20/0xb0 [drm_kms_helper] [ 246.686179] mutex_lock_nested+0x1b/0x20 [ 246.687278] ? mutex_lock_nested+0x1b/0x20 [ 246.688307] drm_fb_helper_hotplug_event.part.28+0x20/0xb0 [drm_kms_helper] [ 246.689420] drm_fb_helper_output_poll_changed+0x23/0x30 [drm_kms_helper] [ 246.690462] drm_kms_helper_hotplug_event+0x2a/0x30 [drm_kms_helper] [ 246.691570] output_poll_execute+0x198/0x1c0 [drm_kms_helper] [ 246.692611] process_one_work+0x231/0x620 [ 246.693725] worker_thread+0x214/0x3a0 [ 246.694756] kthread+0x12b/0x150 [ 246.695856] ? wq_pool_ids_show+0x140/0x140 [ 246.696888] ? kthread_create_worker_on_cpu+0x70/0x70 [ 246.697998] ret_from_fork+0x3a/0x50 [ 246.699034] INFO: task kworker/0:1:60 blocked for more than 120 seconds. [ 246.700153] Not tainted 4.18.0-rc5Lyude-Test+ #2 [ 246.701182] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 246.702278] kworker/0:1 D 0 60 2 0x80000000 [ 246.703293] Workqueue: pm pm_runtime_work [ 246.704393] Call Trace: [ 246.705403] __schedule+0x322/0xaf0 [ 246.706439] ? wait_for_completion+0x104/0x190 [ 246.707393] schedule+0x33/0x90 [ 246.708375] schedule_timeout+0x3a5/0x590 [ 246.709289] ? mark_held_locks+0x58/0x80 [ 246.710208] ? _raw_spin_unlock_irq+0x2c/0x40 [ 246.711222] ? wait_for_completion+0x104/0x190 [ 246.712134] ? trace_hardirqs_on_caller+0xf4/0x190 [ 246.713094] ? wait_for_completion+0x104/0x190 [ 246.713964] wait_for_completion+0x12c/0x190 [ 246.714895] ? wake_up_q+0x80/0x80 [ 246.715727] ? get_work_pool+0x90/0x90 [ 246.716649] flush_work+0x1c9/0x280 [ 246.717483] ? flush_workqueue_prep_pwqs+0x1b0/0x1b0 [ 246.718442] __cancel_work_timer+0x146/0x1d0 [ 246.719247] cancel_delayed_work_sync+0x13/0x20 [ 246.720043] drm_kms_helper_poll_disable+0x1f/0x30 [drm_kms_helper] [ 246.721123] nouveau_pmops_runtime_suspend+0x3d/0xb0 [nouveau] [ 246.721897] pci_pm_runtime_suspend+0x6b/0x190 [ 246.722825] ? pci_has_legacy_pm_support+0x70/0x70 [ 246.723737] __rpm_callback+0x7a/0x1d0 [ 246.724721] ? pci_has_legacy_pm_support+0x70/0x70 [ 246.725607] rpm_callback+0x24/0x80 [ 246.726553] ? pci_has_legacy_pm_support+0x70/0x70 [ 246.727376] rpm_suspend+0x142/0x6b0 [ 246.728185] pm_runtime_work+0x97/0xc0 [ 246.728938] process_one_work+0x231/0x620 [ 246.729796] worker_thread+0x44/0x3a0 [ 246.730614] kthread+0x12b/0x150 [ 246.731395] ? wq_pool_ids_show+0x140/0x140 [ 246.732202] ? kthread_create_worker_on_cpu+0x70/0x70 [ 246.732878] ret_from_fork+0x3a/0x50 [ 246.733768] INFO: task kworker/4:2:422 blocked for more than 120 seconds. [ 246.734587] Not tainted 4.18.0-rc5Lyude-Test+ #2 [ 246.735393] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 246.736113] kworker/4:2 D 0 422 2 0x80000080 [ 246.736789] Workqueue: events_long drm_dp_mst_link_probe_work [drm_kms_helper] [ 246.737665] Call Trace: [ 246.738490] __schedule+0x322/0xaf0 [ 246.739250] schedule+0x33/0x90 [ 246.739908] rpm_resume+0x19c/0x850 [ 246.740750] ? finish_wait+0x90/0x90 [ 246.741541] __pm_runtime_resume+0x4e/0x90 [ 246.742370] nv50_disp_atomic_commit+0x31/0x210 [nouveau] [ 246.743124] drm_atomic_commit+0x4a/0x50 [drm] [ 246.743775] restore_fbdev_mode_atomic+0x1c8/0x240 [drm_kms_helper] [ 246.744603] restore_fbdev_mode+0x31/0x140 [drm_kms_helper] [ 246.745373] drm_fb_helper_restore_fbdev_mode_unlocked+0x54/0xb0 [drm_kms_helper] [ 246.746220] drm_fb_helper_set_par+0x2d/0x50 [drm_kms_helper] [ 246.746884] drm_fb_helper_hotplug_event.part.28+0x96/0xb0 [drm_kms_helper] [ 246.747675] drm_fb_helper_output_poll_changed+0x23/0x30 [drm_kms_helper] [ 246.748544] drm_kms_helper_hotplug_event+0x2a/0x30 [drm_kms_helper] [ 246.749439] nv50_mstm_hotplug+0x15/0x20 [nouveau] [ 246.750111] drm_dp_send_link_address+0x177/0x1c0 [drm_kms_helper] [ 246.750764] drm_dp_check_and_send_link_address+0xa8/0xd0 [drm_kms_helper] [ 246.751602] drm_dp_mst_link_probe_work+0x51/0x90 [drm_kms_helper] [ 246.752314] process_one_work+0x231/0x620 [ 246.752979] worker_thread+0x44/0x3a0 [ 246.753838] kthread+0x12b/0x150 [ 246.754619] ? wq_pool_ids_show+0x140/0x140 [ 246.755386] ? kthread_create_worker_on_cpu+0x70/0x70 [ 246.756162] ret_from_fork+0x3a/0x50 [ 246.756847] Showing all locks held in the system: [ 246.758261] 3 locks held by kworker/4:0/37: [ 246.759016] #0: 00000000f8df4d2d ((wq_completion)"events"){+.+.}, at: process_one_work+0x1b3/0x620 [ 246.759856] #1: 00000000e6065461 ((work_completion)(&(&dev->mode_config.output_poll_work)->work)){+.+.}, at: process_one_work+0x1b3/0x620 [ 246.760670] #2: 00000000cb66735f (&helper->lock){+.+.}, at: drm_fb_helper_hotplug_event.part.28+0x20/0xb0 [drm_kms_helper] [ 246.761516] 2 locks held by kworker/0:1/60: [ 246.762274] #0: 00000000fff6be0f ((wq_completion)"pm"){+.+.}, at: process_one_work+0x1b3/0x620 [ 246.762982] #1: 000000005ab44fb4 ((work_completion)(&dev->power.work)){+.+.}, at: process_one_work+0x1b3/0x620 [ 246.763890] 1 lock held by khungtaskd/64: [ 246.764664] #0: 000000008cb8b5c3 (rcu_read_lock){....}, at: debug_show_all_locks+0x23/0x185 [ 246.765588] 5 locks held by kworker/4:2/422: [ 246.766440] #0: 00000000232f0959 ((wq_completion)"events_long"){+.+.}, at: process_one_work+0x1b3/0x620 [ 246.767390] #1: 00000000bb59b134 ((work_completion)(&mgr->work)){+.+.}, at: process_one_work+0x1b3/0x620 [ 246.768154] #2: 00000000cb66735f (&helper->lock){+.+.}, at: drm_fb_helper_restore_fbdev_mode_unlocked+0x4c/0xb0 [drm_kms_helper] [ 246.768966] #3: 000000004c8f0b6b (crtc_ww_class_acquire){+.+.}, at: restore_fbdev_mode_atomic+0x4b/0x240 [drm_kms_helper] [ 246.769921] #4: 000000004c34a296 (crtc_ww_class_mutex){+.+.}, at: drm_modeset_backoff+0x8a/0x1b0 [drm] [ 246.770839] 1 lock held by dmesg/1038: [ 246.771739] 2 locks held by zsh/1172: [ 246.772650] #0: 00000000836d0438 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 [ 246.773680] #1: 000000001f4f4d48 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0xc1/0x870 [ 246.775522] ============================================= After trying dozens of different solutions, I found one very simple one that should also have the benefit of preventing us from having to fight locking for the rest of our lives. So, we work around these deadlocks by deferring all fbcon hotplug events that happen after the runtime suspend process starts until after the device is resumed again. Changes since v7: - Fixup commit message - Daniel Vetter Changes since v6: - Remove unused nouveau_fbcon_hotplugged_in_suspend() - Ilia Changes since v5: - Come up with the (hopefully final) solution for solving this dumb problem, one that is a lot less likely to cause issues with locking in the future. This should work around all deadlock conditions with fbcon brought up thus far. Changes since v4: - Add nouveau_fbcon_hotplugged_in_suspend() to workaround deadlock condition that Lukas described - Just move all of this out of drm_fb_helper. It seems that other DRM drivers have already figured out other workarounds for this. If other drivers do end up needing this in the future, we can just move this back into drm_fb_helper again. Changes since v3: - Actually check if fb_helper is NULL in both new helpers - Actually check drm_fbdev_emulation in both new helpers - Don't fire off a fb_helper hotplug unconditionally; only do it if the following conditions are true (as otherwise, calling this in the wrong spot will cause Bad Things to happen): - fb_helper hotplug handling was actually inhibited previously - fb_helper actually has a delayed hotplug pending - fb_helper is actually bound - fb_helper is actually initialized - Add __must_check to drm_fb_helper_suspend_hotplug(). There's no situation where a driver would actually want to use this without checking the return value, so enforce that - Rewrite and clarify the documentation for both helpers. - Make sure to return true in the drm_fb_helper_suspend_hotplug() stub that's provided in drm_fb_helper.h when CONFIG_DRM_FBDEV_EMULATION isn't enabled - Actually grab the toplevel fb_helper lock in drm_fb_helper_resume_hotplug(), since it's possible other activity (such as a hotplug) could be going on at the same time the driver calls drm_fb_helper_resume_hotplug(). We need this to check whether or not drm_fb_helper_hotplug_event() needs to be called anyway Signed-off-by: Lyude Paul <lyude@redhat.com> Reviewed-by: Karol Herbst <kherbst@redhat.com> Acked-by: Daniel Vetter <daniel@ffwll.ch> Cc: stable@vger.kernel.org Cc: Lukas Wunner <lukas@wunner.de> Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

When we disable hotplugging on the GPU, we need to be able to synchronize with each connector's hotplug interrupt handler before the interrupt is finally disabled. This can be a problem however, since nouveau_connector_detect() currently grabs a runtime power reference when handling connector probing. This will deadlock the runtime suspend handler like so: [ 861.480896] INFO: task kworker/0:2:61 blocked for more than 120 seconds. [ 861.483290] Tainted: G O 4.18.0-rc6Lyude-Test+ #1 [ 861.485158] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 861.486332] kworker/0:2 D 0 61 2 0x80000000 [ 861.487044] Workqueue: events nouveau_display_hpd_work [nouveau] [ 861.487737] Call Trace: [ 861.488394] __schedule+0x322/0xaf0 [ 861.489070] schedule+0x33/0x90 [ 861.489744] rpm_resume+0x19c/0x850 [ 861.490392] ? finish_wait+0x90/0x90 [ 861.491068] __pm_runtime_resume+0x4e/0x90 [ 861.491753] nouveau_display_hpd_work+0x22/0x60 [nouveau] [ 861.492416] process_one_work+0x231/0x620 [ 861.493068] worker_thread+0x44/0x3a0 [ 861.493722] kthread+0x12b/0x150 [ 861.494342] ? wq_pool_ids_show+0x140/0x140 [ 861.494991] ? kthread_create_worker_on_cpu+0x70/0x70 [ 861.495648] ret_from_fork+0x3a/0x50 [ 861.496304] INFO: task kworker/6:2:320 blocked for more than 120 seconds. [ 861.496968] Tainted: G O 4.18.0-rc6Lyude-Test+ #1 [ 861.497654] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 861.498341] kworker/6:2 D 0 320 2 0x80000080 [ 861.499045] Workqueue: pm pm_runtime_work [ 861.499739] Call Trace: [ 861.500428] __schedule+0x322/0xaf0 [ 861.501134] ? wait_for_completion+0x104/0x190 [ 861.501851] schedule+0x33/0x90 [ 861.502564] schedule_timeout+0x3a5/0x590 [ 861.503284] ? mark_held_locks+0x58/0x80 [ 861.503988] ? _raw_spin_unlock_irq+0x2c/0x40 [ 861.504710] ? wait_for_completion+0x104/0x190 [ 861.505417] ? trace_hardirqs_on_caller+0xf4/0x190 [ 861.506136] ? wait_for_completion+0x104/0x190 [ 861.506845] wait_for_completion+0x12c/0x190 [ 861.507555] ? wake_up_q+0x80/0x80 [ 861.508268] flush_work+0x1c9/0x280 [ 861.508990] ? flush_workqueue_prep_pwqs+0x1b0/0x1b0 [ 861.509735] nvif_notify_put+0xb1/0xc0 [nouveau] [ 861.510482] nouveau_display_fini+0xbd/0x170 [nouveau] [ 861.511241] nouveau_display_suspend+0x67/0x120 [nouveau] [ 861.511969] nouveau_do_suspend+0x5e/0x2d0 [nouveau] [ 861.512715] nouveau_pmops_runtime_suspend+0x47/0xb0 [nouveau] [ 861.513435] pci_pm_runtime_suspend+0x6b/0x180 [ 861.514165] ? pci_has_legacy_pm_support+0x70/0x70 [ 861.514897] __rpm_callback+0x7a/0x1d0 [ 861.515618] ? pci_has_legacy_pm_support+0x70/0x70 [ 861.516313] rpm_callback+0x24/0x80 [ 861.517027] ? pci_has_legacy_pm_support+0x70/0x70 [ 861.517741] rpm_suspend+0x142/0x6b0 [ 861.518449] pm_runtime_work+0x97/0xc0 [ 861.519144] process_one_work+0x231/0x620 [ 861.519831] worker_thread+0x44/0x3a0 [ 861.520522] kthread+0x12b/0x150 [ 861.521220] ? wq_pool_ids_show+0x140/0x140 [ 861.521925] ? kthread_create_worker_on_cpu+0x70/0x70 [ 861.522622] ret_from_fork+0x3a/0x50 [ 861.523299] INFO: task kworker/6:0:1329 blocked for more than 120 seconds. [ 861.523977] Tainted: G O 4.18.0-rc6Lyude-Test+ #1 [ 861.524644] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 861.525349] kworker/6:0 D 0 1329 2 0x80000000 [ 861.526073] Workqueue: events nvif_notify_work [nouveau] [ 861.526751] Call Trace: [ 861.527411] __schedule+0x322/0xaf0 [ 861.528089] schedule+0x33/0x90 [ 861.528758] rpm_resume+0x19c/0x850 [ 861.529399] ? finish_wait+0x90/0x90 [ 861.530073] __pm_runtime_resume+0x4e/0x90 [ 861.530798] nouveau_connector_detect+0x7e/0x510 [nouveau] [ 861.531459] ? ww_mutex_lock+0x47/0x80 [ 861.532097] ? ww_mutex_lock+0x47/0x80 [ 861.532819] ? drm_modeset_lock+0x88/0x130 [drm] [ 861.533481] drm_helper_probe_detect_ctx+0xa0/0x100 [drm_kms_helper] [ 861.534127] drm_helper_hpd_irq_event+0xa4/0x120 [drm_kms_helper] [ 861.534940] nouveau_connector_hotplug+0x98/0x120 [nouveau] [ 861.535556] nvif_notify_work+0x2d/0xb0 [nouveau] [ 861.536221] process_one_work+0x231/0x620 [ 861.536994] worker_thread+0x44/0x3a0 [ 861.537757] kthread+0x12b/0x150 [ 861.538463] ? wq_pool_ids_show+0x140/0x140 [ 861.539102] ? kthread_create_worker_on_cpu+0x70/0x70 [ 861.539815] ret_from_fork+0x3a/0x50 [ 861.540521] Showing all locks held in the system: [ 861.541696] 2 locks held by kworker/0:2/61: [ 861.542406] #0: 000000002dbf8af5 ((wq_completion)"events"){+.+.}, at: process_one_work+0x1b3/0x620 [ 861.543071] #1: 0000000076868126 ((work_completion)(&drm->hpd_work)){+.+.}, at: process_one_work+0x1b3/0x620 [ 861.543814] 1 lock held by khungtaskd/64: [ 861.544535] #0: 0000000059db4b53 (rcu_read_lock){....}, at: debug_show_all_locks+0x23/0x185 [ 861.545160] 3 locks held by kworker/6:2/320: [ 861.545896] #0: 00000000d9e1bc59 ((wq_completion)"pm"){+.+.}, at: process_one_work+0x1b3/0x620 [ 861.546702] #1: 00000000c9f92d84 ((work_completion)(&dev->power.work)){+.+.}, at: process_one_work+0x1b3/0x620 [ 861.547443] #2: 000000004afc5de1 (drm_connector_list_iter){.+.+}, at: nouveau_display_fini+0x96/0x170 [nouveau] [ 861.548146] 1 lock held by dmesg/983: [ 861.548889] 2 locks held by zsh/1250: [ 861.549605] #0: 00000000348e3cf6 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 [ 861.550393] #1: 000000007009a7a8 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0xc1/0x870 [ 861.551122] 6 locks held by kworker/6:0/1329: [ 861.551957] #0: 000000002dbf8af5 ((wq_completion)"events"){+.+.}, at: process_one_work+0x1b3/0x620 [ 861.552765] #1: 00000000ddb499ad ((work_completion)(&notify->work)#2){+.+.}, at: process_one_work+0x1b3/0x620 [ 861.553582] #2: 000000006e013cbe (&dev->mode_config.mutex){+.+.}, at: drm_helper_hpd_irq_event+0x6c/0x120 [drm_kms_helper] [ 861.554357] #3: 000000004afc5de1 (drm_connector_list_iter){.+.+}, at: drm_helper_hpd_irq_event+0x78/0x120 [drm_kms_helper] [ 861.555227] #4: 0000000044f294d9 (crtc_ww_class_acquire){+.+.}, at: drm_helper_probe_detect_ctx+0x3d/0x100 [drm_kms_helper] [ 861.556133] #5: 00000000db193642 (crtc_ww_class_mutex){+.+.}, at: drm_modeset_lock+0x4b/0x130 [drm] [ 861.557864] ============================================= [ 861.559507] NMI backtrace for cpu 2 [ 861.560363] CPU: 2 PID: 64 Comm: khungtaskd Tainted: G O 4.18.0-rc6Lyude-Test+ #1 [ 861.561197] Hardware name: LENOVO 20EQS64N0B/20EQS64N0B, BIOS N1EET78W (1.51 ) 05/18/2018 [ 861.561948] Call Trace: [ 861.562757] dump_stack+0x8e/0xd3 [ 861.563516] nmi_cpu_backtrace.cold.3+0x14/0x5a [ 861.564269] ? lapic_can_unplug_cpu.cold.27+0x42/0x42 [ 861.565029] nmi_trigger_cpumask_backtrace+0xa1/0xae [ 861.565789] arch_trigger_cpumask_backtrace+0x19/0x20 [ 861.566558] watchdog+0x316/0x580 [ 861.567355] kthread+0x12b/0x150 [ 861.568114] ? reset_hung_task_detector+0x20/0x20 [ 861.568863] ? kthread_create_worker_on_cpu+0x70/0x70 [ 861.569598] ret_from_fork+0x3a/0x50 [ 861.570370] Sending NMI from CPU 2 to CPUs 0-1,3-7: [ 861.571426] NMI backtrace for cpu 6 skipped: idling at intel_idle+0x7f/0x120 [ 861.571429] NMI backtrace for cpu 7 skipped: idling at intel_idle+0x7f/0x120 [ 861.571432] NMI backtrace for cpu 3 skipped: idling at intel_idle+0x7f/0x120 [ 861.571464] NMI backtrace for cpu 5 skipped: idling at intel_idle+0x7f/0x120 [ 861.571467] NMI backtrace for cpu 0 skipped: idling at intel_idle+0x7f/0x120 [ 861.571469] NMI backtrace for cpu 4 skipped: idling at intel_idle+0x7f/0x120 [ 861.571472] NMI backtrace for cpu 1 skipped: idling at intel_idle+0x7f/0x120 [ 861.572428] Kernel panic - not syncing: hung_task: blocked tasks So: fix this by making it so that normal hotplug handling /only/ happens so long as the GPU is currently awake without any pending runtime PM requests. In the event that a hotplug occurs while the device is suspending or resuming, we can simply defer our response until the GPU is fully runtime resumed again. Changes since v4: - Use a new trick I came up with using pm_runtime_get() instead of the hackish junk we had before Signed-off-by: Lyude Paul <lyude@redhat.com> Reviewed-by: Karol Herbst <kherbst@redhat.com> Acked-by: Daniel Vetter <daniel@ffwll.ch> Cc: stable@vger.kernel.org Cc: Lukas Wunner <lukas@wunner.de> Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

Commit 822fb18 ("xen-netfront: wait xenbus state change when load module manually") added a new wait queue to wait on for a state change when the module is loaded manually. Unfortunately there is no wakeup anywhere to stop that waiting. Instead of introducing a new wait queue rename the existing module_unload_q to module_wq and use it for both purposes (loading and unloading). As any state change of the backend might be intended to stop waiting do the wake_up_all() in any case when netback_changed() is called. Fixes: 822fb18 ("xen-netfront: wait xenbus state change when load module manually") Cc: <stable@vger.kernel.org> #4.18 Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>

In case local OOB data was generated and other device initiated pairing claiming that it has got OOB data, following crash occurred: [ 222.847853] general protection fault: 0000 [#1] SMP PTI [ 222.848025] CPU: 1 PID: 42 Comm: kworker/u5:0 Tainted: G C 4.18.0-custom #4 [ 222.848158] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 [ 222.848307] Workqueue: hci0 hci_rx_work [bluetooth] [ 222.848416] RIP: 0010:compute_ecdh_secret+0x5a/0x270 [bluetooth] [ 222.848540] Code: 0c af f5 48 8b 3d 46 de f0 f6 ba 40 00 00 00 be c0 00 60 00 e8 b7 7b c5 f5 48 85 c0 0f 84 ea 01 00 00 48 89 c3 e8 16 0c af f5 <49> 8b 47 38 be c0 00 60 00 8b 78 f8 48 83 c7 48 e8 51 84 c5 f5 48 [ 222.848914] RSP: 0018:ffffb1664087fbc0 EFLAGS: 00010293 [ 222.849021] RAX: ffff8a5750d7dc00 RBX: ffff8a5671096780 RCX: ffffffffc08bc32a [ 222.849111] RDX: 0000000000000000 RSI: 00000000006000c0 RDI: ffff8a5752003800 [ 222.849192] RBP: ffffb1664087fc60 R08: ffff8a57525280a0 R09: ffff8a5752003800 [ 222.849269] R10: ffffb1664087fc70 R11: 0000000000000093 R12: ffff8a5674396e00 [ 222.849350] R13: ffff8a574c2e79aa R14: ffff8a574c2e796a R15: 020e0e100d010101 [ 222.849429] FS: 0000000000000000(0000) GS:ffff8a5752500000(0000) knlGS:0000000000000000 [ 222.849518] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 222.849586] CR2: 000055856016a038 CR3: 0000000110d2c005 CR4: 00000000000606e0 [ 222.849671] Call Trace: [ 222.849745] ? sc_send_public_key+0x110/0x2a0 [bluetooth] [ 222.849825] ? sc_send_public_key+0x115/0x2a0 [bluetooth] [ 222.849925] smp_recv_cb+0x959/0x2490 [bluetooth] [ 222.850023] ? _cond_resched+0x19/0x40 [ 222.850105] ? mutex_lock+0x12/0x40 [ 222.850202] l2cap_recv_frame+0x109d/0x3420 [bluetooth] [ 222.850315] ? l2cap_recv_frame+0x109d/0x3420 [bluetooth] [ 222.850426] ? __switch_to_asm+0x34/0x70 [ 222.850515] ? __switch_to_asm+0x40/0x70 [ 222.850625] ? __switch_to_asm+0x34/0x70 [ 222.850724] ? __switch_to_asm+0x40/0x70 [ 222.850786] ? __switch_to_asm+0x34/0x70 [ 222.850846] ? __switch_to_asm+0x40/0x70 [ 222.852581] ? __switch_to_asm+0x34/0x70 [ 222.854976] ? __switch_to_asm+0x40/0x70 [ 222.857475] ? __switch_to_asm+0x40/0x70 [ 222.859775] ? __switch_to_asm+0x34/0x70 [ 222.861218] ? __switch_to_asm+0x40/0x70 [ 222.862327] ? __switch_to_asm+0x34/0x70 [ 222.863758] l2cap_recv_acldata+0x266/0x3c0 [bluetooth] [ 222.865122] hci_rx_work+0x1c9/0x430 [bluetooth] [ 222.867144] process_one_work+0x210/0x4c0 [ 222.868248] worker_thread+0x41/0x4d0 [ 222.869420] kthread+0x141/0x160 [ 222.870694] ? process_one_work+0x4c0/0x4c0 [ 222.871668] ? kthread_create_worker_on_cpu+0x90/0x90 [ 222.872896] ret_from_fork+0x35/0x40 [ 222.874132] Modules linked in: algif_hash algif_skcipher af_alg rfcomm bnep btusb btrtl btbcm btintel snd_intel8x0 cmac intel_rapl_perf vboxvideo(C) snd_ac97_codec bluetooth ac97_bus joydev ttm snd_pcm ecdh_generic drm_kms_helper snd_timer snd input_leds drm serio_raw fb_sys_fops soundcore syscopyarea sysfillrect sysimgblt mac_hid sch_fq_codel ib_iser rdma_cm iw_cm ib_cm ib_core iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi ip_tables x_tables autofs4 btrfs zstd_compress raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c raid1 raid0 multipath linear hid_generic usbhid hid crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcbc aesni_intel aes_x86_64 crypto_simd cryptd glue_helper ahci psmouse libahci i2c_piix4 video e1000 pata_acpi [ 222.883153] fbcon_switch: detected unhandled fb_set_par error, error code -16 [ 222.886774] fbcon_switch: detected unhandled fb_set_par error, error code -16 [ 222.890503] ---[ end trace 6504aa7a777b5316 ]--- [ 222.890541] RIP: 0010:compute_ecdh_secret+0x5a/0x270 [bluetooth] [ 222.890551] Code: 0c af f5 48 8b 3d 46 de f0 f6 ba 40 00 00 00 be c0 00 60 00 e8 b7 7b c5 f5 48 85 c0 0f 84 ea 01 00 00 48 89 c3 e8 16 0c af f5 <49> 8b 47 38 be c0 00 60 00 8b 78 f8 48 83 c7 48 e8 51 84 c5 f5 48 [ 222.890555] RSP: 0018:ffffb1664087fbc0 EFLAGS: 00010293 [ 222.890561] RAX: ffff8a5750d7dc00 RBX: ffff8a5671096780 RCX: ffffffffc08bc32a [ 222.890565] RDX: 0000000000000000 RSI: 00000000006000c0 RDI: ffff8a5752003800 [ 222.890571] RBP: ffffb1664087fc60 R08: ffff8a57525280a0 R09: ffff8a5752003800 [ 222.890576] R10: ffffb1664087fc70 R11: 0000000000000093 R12: ffff8a5674396e00 [ 222.890581] R13: ffff8a574c2e79aa R14: ffff8a574c2e796a R15: 020e0e100d010101 [ 222.890586] FS: 0000000000000000(0000) GS:ffff8a5752500000(0000) knlGS:0000000000000000 [ 222.890591] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 222.890594] CR2: 000055856016a038 CR3: 0000000110d2c005 CR4: 00000000000606e0 This commit fixes a bug where invalid pointer to crypto tfm was used for SMP SC ECDH calculation when OOB was in use. Solution is to use same crypto tfm than when generating OOB material on generate_oob() function. This bug was introduced in commit c0153b0 ("Bluetooth: let the crypto subsystem generate the ecc privkey"). Bug was found by fuzzing kernel SMP implementation using Synopsys Defensics. Signed-off-by: Matias Karhumaa <matias.karhumaa@gmail.com> Signed-off-by: Johan Hedberg <johan.hedberg@intel.com> Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

When netvsc device is removed it can call reschedule in RCU context. This happens because canceling the subchannel setup work could (in theory) cause a reschedule when manipulating the timer. To reproduce, run with lockdep enabled kernel and unbind a network device from hv_netvsc (via sysfs). [ 160.682011] WARNING: suspicious RCU usage [ 160.707466] 4.19.0-rc3-uio+ #2 Not tainted [ 160.709937] ----------------------------- [ 160.712352] ./include/linux/rcupdate.h:302 Illegal context switch in RCU read-side critical section! [ 160.723691] [ 160.723691] other info that might help us debug this: [ 160.723691] [ 160.730955] [ 160.730955] rcu_scheduler_active = 2, debug_locks = 1 [ 160.762813] 5 locks held by rebind-eth.sh/1812: [ 160.766851] #0: 000000008befa37a (sb_writers#6){.+.+}, at: vfs_write+0x184/0x1b0 [ 160.773416] #1: 00000000b097f236 (&of->mutex){+.+.}, at: kernfs_fop_write+0xe2/0x1a0 [ 160.783766] #2: 0000000041ee6889 (kn->count#3){++++}, at: kernfs_fop_write+0xeb/0x1a0 [ 160.787465] #3: 0000000056d92a74 (&dev->mutex){....}, at: device_release_driver_internal+0x39/0x250 [ 160.816987] #4: 0000000030f6031e (rcu_read_lock){....}, at: netvsc_remove+0x1e/0x250 [hv_netvsc] [ 160.828629] [ 160.828629] stack backtrace: [ 160.831966] CPU: 1 PID: 1812 Comm: rebind-eth.sh Not tainted 4.19.0-rc3-uio+ #2 [ 160.832952] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v1.0 11/26/2012 [ 160.832952] Call Trace: [ 160.832952] dump_stack+0x85/0xcb [ 160.832952] ___might_sleep+0x1a3/0x240 [ 160.832952] __flush_work+0x57/0x2e0 [ 160.832952] ? __mutex_lock+0x83/0x990 [ 160.832952] ? __kernfs_remove+0x24f/0x2e0 [ 160.832952] ? __kernfs_remove+0x1b2/0x2e0 [ 160.832952] ? mark_held_locks+0x50/0x80 [ 160.832952] ? get_work_pool+0x90/0x90 [ 160.832952] __cancel_work_timer+0x13c/0x1e0 [ 160.832952] ? netvsc_remove+0x1e/0x250 [hv_netvsc] [ 160.832952] ? __lock_is_held+0x55/0x90 [ 160.832952] netvsc_remove+0x9a/0x250 [hv_netvsc] [ 160.832952] vmbus_remove+0x26/0x30 [ 160.832952] device_release_driver_internal+0x18a/0x250 [ 160.832952] unbind_store+0xb4/0x180 [ 160.832952] kernfs_fop_write+0x113/0x1a0 [ 160.832952] __vfs_write+0x36/0x1a0 [ 160.832952] ? rcu_read_lock_sched_held+0x6b/0x80 [ 160.832952] ? rcu_sync_lockdep_assert+0x2e/0x60 [ 160.832952] ? __sb_start_write+0x141/0x1a0 [ 160.832952] ? vfs_write+0x184/0x1b0 [ 160.832952] vfs_write+0xbe/0x1b0 [ 160.832952] ksys_write+0x55/0xc0 [ 160.832952] do_syscall_64+0x60/0x1b0 [ 160.832952] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 160.832952] RIP: 0033:0x7fe48f4c8154 Resolve this by getting RTNL earlier. This is safe because the subchannel work queue does trylock on RTNL and will detect the race. Fixes: 7b2ee50 ("hv_netvsc: common detach logic") Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com> Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com> Signed-off-by: David S. Miller <davem@davemloft.net>

Like evlist cpu map, evsel's cpu map should have a proper refcount. As it's created with a refcount, we don't need to get an extra count. Thanks to Arnaldo for the simpler suggestion. This, together with the following patch, fixes the following ASAN report: Direct leak of 840 byte(s) in 70 object(s) allocated from: #0 0x7fe36703f628 in malloc (/lib/x86_64-linux-gnu/libasan.so.5+0x107628) #1 0x559fbbf611ca in cpu_map__trim_new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:79 #2 0x559fbbf6229c in perf_cpu_map__new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:237 #3 0x559fbbcc6c6d in __add_event util/parse-events.c:357 #4 0x559fbbcc6c6d in add_event_tool util/parse-events.c:408 #5 0x559fbbcc6c6d in parse_events_add_tool util/parse-events.c:1414 #6 0x559fbbd8474d in parse_events_parse util/parse-events.y:439 #7 0x559fbbcc95da in parse_events__scanner util/parse-events.c:2096 #8 0x559fbbcc95da in __parse_events util/parse-events.c:2141 #9 0x559fbbc2788b in check_parse_id tests/pmu-events.c:406 #10 0x559fbbc2788b in check_parse_id tests/pmu-events.c:393 #11 0x559fbbc2788b in check_parse_fake tests/pmu-events.c:436 #12 0x559fbbc2788b in metric_parse_fake tests/pmu-events.c:553 #13 0x559fbbc27e2d in test_parsing_fake tests/pmu-events.c:599 #14 0x559fbbc27e2d in test_parsing_fake tests/pmu-events.c:574 #15 0x559fbbc0109b in run_test tests/builtin-test.c:410 #16 0x559fbbc0109b in test_and_print tests/builtin-test.c:440 #17 0x559fbbc03e69 in __cmd_test tests/builtin-test.c:695 #18 0x559fbbc03e69 in cmd_test tests/builtin-test.c:807 #19 0x559fbbc691f4 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:312 #20 0x559fbbb071a8 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:364 #21 0x559fbbb071a8 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:408 #22 0x559fbbb071a8 in main /home/namhyung/project/linux/tools/perf/perf.c:538 #23 0x7fe366b68cc9 in __libc_start_main ../csu/libc-start.c:308 And I've failed which commit introduced this bug as the code was heavily changed since then. ;-/ Signed-off-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Jiri Olsa <jolsa@redhat.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lore.kernel.org/lkml/20200917060219.1287863-2-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Ensure 'st' is initialized before an error branch is taken. Fixes test "67: Parse and process metrics" with LLVM msan: ==6757==WARNING: MemorySanitizer: use-of-uninitialized-value #0 0x5570edae947d in rblist__exit tools/perf/util/rblist.c:114:2 #1 0x5570edb1c6e8 in runtime_stat__exit tools/perf/util/stat-shadow.c:141:2 #2 0x5570ed92cfae in __compute_metric tools/perf/tests/parse-metric.c:187:2 #3 0x5570ed92cb74 in compute_metric tools/perf/tests/parse-metric.c:196:9 #4 0x5570ed92c6d8 in test_recursion_fail tools/perf/tests/parse-metric.c:318:2 #5 0x5570ed92b8c8 in test__parse_metric tools/perf/tests/parse-metric.c:356:2 #6 0x5570ed8de8c1 in run_test tools/perf/tests/builtin-test.c:410:9 #7 0x5570ed8ddadf in test_and_print tools/perf/tests/builtin-test.c:440:9 #8 0x5570ed8dca04 in __cmd_test tools/perf/tests/builtin-test.c:661:4 #9 0x5570ed8dbc07 in cmd_test tools/perf/tests/builtin-test.c:807:9 #10 0x5570ed7326cc in run_builtin tools/perf/perf.c:313:11 #11 0x5570ed731639 in handle_internal_command tools/perf/perf.c:365:8 #12 0x5570ed7323cd in run_argv tools/perf/perf.c:409:2 #13 0x5570ed731076 in main tools/perf/perf.c:539:3 Fixes: commit f5a5657 ("perf test: Fix memory leaks in parse-metric test") Signed-off-by: Ian Rogers <irogers@google.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: clang-built-linux@googlegroups.com Link: http://lore.kernel.org/lkml/20200923210655.4143682-1-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

…vents It was reported that 'perf stat' crashed when using with armv8_pmu (CPU) events with the task mode. As 'perf stat' uses an empty cpu map for task mode but armv8_pmu has its own cpu mask, it has confused which map it should use when accessing file descriptors and this causes segfaults: (gdb) bt #0 0x0000000000603fc8 in perf_evsel__close_fd_cpu (evsel=<optimized out>, cpu=<optimized out>) at evsel.c:122 #1 perf_evsel__close_cpu (evsel=evsel@entry=0x716e950, cpu=7) at evsel.c:156 #2 0x00000000004d4718 in evlist__close (evlist=0x70a7cb0) at util/evlist.c:1242 #3 0x0000000000453404 in __run_perf_stat (argc=3, argc@entry=1, argv=0x30, argv@entry=0xfffffaea2f90, run_idx=119, run_idx@entry=1701998435) at builtin-stat.c:929 #4 0x0000000000455058 in run_perf_stat (run_idx=1701998435, argv=0xfffffaea2f90, argc=1) at builtin-stat.c:947 #5 cmd_stat (argc=1, argv=0xfffffaea2f90) at builtin-stat.c:2357 #6 0x00000000004bb888 in run_builtin (p=p@entry=0x9764b8 <commands+288>, argc=argc@entry=4, argv=argv@entry=0xfffffaea2f90) at perf.c:312 #7 0x00000000004bbb54 in handle_internal_command (argc=argc@entry=4, argv=argv@entry=0xfffffaea2f90) at perf.c:364 #8 0x0000000000435378 in run_argv (argcp=<synthetic pointer>, argv=<synthetic pointer>) at perf.c:408 #9 main (argc=4, argv=0xfffffaea2f90) at perf.c:538 To fix this, I simply used the given cpu map unless the evsel actually is not a system-wide event (like uncore events). Fixes: 7736627 ("perf stat: Use affinity for closing file descriptors") Reported-by: Wei Li <liwei391@huawei.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org> Tested-by: Barry Song <song.bao.hua@hisilicon.com> Acked-by: Jiri Olsa <jolsa@redhat.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lore.kernel.org/lkml/20201007081311.1831003-1-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Dave reported a problem with my rwsem conversion patch where we got the following lockdep splat: ====================================================== WARNING: possible circular locking dependency detected 5.9.0-default+ #1297 Not tainted ------------------------------------------------------ kswapd0/76 is trying to acquire lock: ffff9d5d25df2530 (&delayed_node->mutex){+.+.}-{3:3}, at: __btrfs_release_delayed_node.part.0+0x3f/0x320 [btrfs] but task is already holding lock: ffffffffa40cbba0 (fs_reclaim){+.+.}-{0:0}, at: __fs_reclaim_acquire+0x5/0x30 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (fs_reclaim){+.+.}-{0:0}: __lock_acquire+0x582/0xac0 lock_acquire+0xca/0x430 fs_reclaim_acquire.part.0+0x25/0x30 kmem_cache_alloc+0x30/0x9c0 alloc_inode+0x81/0x90 iget_locked+0xcd/0x1a0 kernfs_get_inode+0x1b/0x130 kernfs_get_tree+0x136/0x210 sysfs_get_tree+0x1a/0x50 vfs_get_tree+0x1d/0xb0 path_mount+0x70f/0xa80 do_mount+0x75/0x90 __x64_sys_mount+0x8e/0xd0 do_syscall_64+0x2d/0x70 entry_SYSCALL_64_after_hwframe+0x44/0xa9 -> #3 (kernfs_mutex){+.+.}-{3:3}: __lock_acquire+0x582/0xac0 lock_acquire+0xca/0x430 __mutex_lock+0xa0/0xaf0 kernfs_add_one+0x23/0x150 kernfs_create_dir_ns+0x58/0x80 sysfs_create_dir_ns+0x70/0xd0 kobject_add_internal+0xbb/0x2d0 kobject_add+0x7a/0xd0 btrfs_sysfs_add_block_group_type+0x141/0x1d0 [btrfs] btrfs_read_block_groups+0x1f1/0x8c0 [btrfs] open_ctree+0x981/0x1108 [btrfs] btrfs_mount_root.cold+0xe/0xb0 [btrfs] legacy_get_tree+0x2d/0x60 vfs_get_tree+0x1d/0xb0 fc_mount+0xe/0x40 vfs_kern_mount.part.0+0x71/0x90 btrfs_mount+0x13b/0x3e0 [btrfs] legacy_get_tree+0x2d/0x60 vfs_get_tree+0x1d/0xb0 path_mount+0x70f/0xa80 do_mount+0x75/0x90 __x64_sys_mount+0x8e/0xd0 do_syscall_64+0x2d/0x70 entry_SYSCALL_64_after_hwframe+0x44/0xa9 -> #2 (btrfs-extent-00){++++}-{3:3}: __lock_acquire+0x582/0xac0 lock_acquire+0xca/0x430 down_read_nested+0x45/0x220 __btrfs_tree_read_lock+0x35/0x1c0 [btrfs] __btrfs_read_lock_root_node+0x3a/0x50 [btrfs] btrfs_search_slot+0x6d4/0xfd0 [btrfs] check_committed_ref+0x69/0x200 [btrfs] btrfs_cross_ref_exist+0x65/0xb0 [btrfs] run_delalloc_nocow+0x446/0x9b0 [btrfs] btrfs_run_delalloc_range+0x61/0x6a0 [btrfs] writepage_delalloc+0xae/0x160 [btrfs] __extent_writepage+0x262/0x420 [btrfs] extent_write_cache_pages+0x2b6/0x510 [btrfs] extent_writepages+0x43/0x90 [btrfs] do_writepages+0x40/0xe0 __writeback_single_inode+0x62/0x610 writeback_sb_inodes+0x20f/0x500 wb_writeback+0xef/0x4a0 wb_do_writeback+0x49/0x2e0 wb_workfn+0x81/0x340 process_one_work+0x233/0x5d0 worker_thread+0x50/0x3b0 kthread+0x137/0x150 ret_from_fork+0x1f/0x30 -> #1 (btrfs-fs-00){++++}-{3:3}: __lock_acquire+0x582/0xac0 lock_acquire+0xca/0x430 down_read_nested+0x45/0x220 __btrfs_tree_read_lock+0x35/0x1c0 [btrfs] __btrfs_read_lock_root_node+0x3a/0x50 [btrfs] btrfs_search_slot+0x6d4/0xfd0 [btrfs] btrfs_lookup_inode+0x3a/0xc0 [btrfs] __btrfs_update_delayed_inode+0x93/0x2c0 [btrfs] __btrfs_commit_inode_delayed_items+0x7de/0x850 [btrfs] __btrfs_run_delayed_items+0x8e/0x140 [btrfs] btrfs_commit_transaction+0x367/0xbc0 [btrfs] btrfs_mksubvol+0x2db/0x470 [btrfs] btrfs_mksnapshot+0x7b/0xb0 [btrfs] __btrfs_ioctl_snap_create+0x16f/0x1a0 [btrfs] btrfs_ioctl_snap_create_v2+0xb0/0xf0 [btrfs] btrfs_ioctl+0xd0b/0x2690 [btrfs] __x64_sys_ioctl+0x6f/0xa0 do_syscall_64+0x2d/0x70 entry_SYSCALL_64_after_hwframe+0x44/0xa9 -> #0 (&delayed_node->mutex){+.+.}-{3:3}: check_prev_add+0x91/0xc60 validate_chain+0xa6e/0x2a20 __lock_acquire+0x582/0xac0 lock_acquire+0xca/0x430 __mutex_lock+0xa0/0xaf0 __btrfs_release_delayed_node.part.0+0x3f/0x320 [btrfs] btrfs_evict_inode+0x3cc/0x560 [btrfs] evict+0xd6/0x1c0 dispose_list+0x48/0x70 prune_icache_sb+0x54/0x80 super_cache_scan+0x121/0x1a0 do_shrink_slab+0x16d/0x3b0 shrink_slab+0xb1/0x2e0 shrink_node+0x230/0x6a0 balance_pgdat+0x325/0x750 kswapd+0x206/0x4d0 kthread+0x137/0x150 ret_from_fork+0x1f/0x30 other info that might help us debug this: Chain exists of: &delayed_node->mutex --> kernfs_mutex --> fs_reclaim Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(fs_reclaim); lock(kernfs_mutex); lock(fs_reclaim); lock(&delayed_node->mutex); *** DEADLOCK *** 3 locks held by kswapd0/76: #0: ffffffffa40cbba0 (fs_reclaim){+.+.}-{0:0}, at: __fs_reclaim_acquire+0x5/0x30 #1: ffffffffa40b8b58 (shrinker_rwsem){++++}-{3:3}, at: shrink_slab+0x54/0x2e0 #2: ffff9d5d322390e8 (&type->s_umount_key#26){++++}-{3:3}, at: trylock_super+0x16/0x50 stack backtrace: CPU: 2 PID: 76 Comm: kswapd0 Not tainted 5.9.0-default+ #1297 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba527-rebuilt.opensuse.org 04/01/2014 Call Trace: dump_stack+0x77/0x97 check_noncircular+0xff/0x110 ? save_trace+0x50/0x470 check_prev_add+0x91/0xc60 validate_chain+0xa6e/0x2a20 ? save_trace+0x50/0x470 __lock_acquire+0x582/0xac0 lock_acquire+0xca/0x430 ? __btrfs_release_delayed_node.part.0+0x3f/0x320 [btrfs] __mutex_lock+0xa0/0xaf0 ? __btrfs_release_delayed_node.part.0+0x3f/0x320 [btrfs] ? __lock_acquire+0x582/0xac0 ? __btrfs_release_delayed_node.part.0+0x3f/0x320 [btrfs] ? btrfs_evict_inode+0x30b/0x560 [btrfs] ? __btrfs_release_delayed_node.part.0+0x3f/0x320 [btrfs] __btrfs_release_delayed_node.part.0+0x3f/0x320 [btrfs] btrfs_evict_inode+0x3cc/0x560 [btrfs] evict+0xd6/0x1c0 dispose_list+0x48/0x70 prune_icache_sb+0x54/0x80 super_cache_scan+0x121/0x1a0 do_shrink_slab+0x16d/0x3b0 shrink_slab+0xb1/0x2e0 shrink_node+0x230/0x6a0 balance_pgdat+0x325/0x750 kswapd+0x206/0x4d0 ? finish_wait+0x90/0x90 ? balance_pgdat+0x750/0x750 kthread+0x137/0x150 ? kthread_mod_delayed_work+0xc0/0xc0 ret_from_fork+0x1f/0x30 This happens because we are still holding the path open when we start adding the sysfs files for the block groups, which creates a dependency on fs_reclaim via the tree lock. Fix this by dropping the path before we start doing anything with sysfs. Reported-by: David Sterba <dsterba@suse.com> CC: stable@vger.kernel.org # 5.8+ Reviewed-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>

Very sporadically I had test case btrfs/069 from fstests hanging (for years, it is not a recent regression), with the following traces in dmesg/syslog: [162301.160628] BTRFS info (device sdc): dev_replace from /dev/sdd (devid 2) to /dev/sdg started [162301.181196] BTRFS info (device sdc): scrub: finished on devid 4 with status: 0 [162301.287162] BTRFS info (device sdc): dev_replace from /dev/sdd (devid 2) to /dev/sdg finished [162513.513792] INFO: task btrfs-transacti:1356167 blocked for more than 120 seconds. [162513.514318] Not tainted 5.9.0-rc6-btrfs-next-69 #1 [162513.514522] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [162513.514747] task:btrfs-transacti state:D stack: 0 pid:1356167 ppid: 2 flags:0x00004000 [162513.514751] Call Trace: [162513.514761] __schedule+0x5ce/0xd00 [162513.514765] ? _raw_spin_unlock_irqrestore+0x3c/0x60 [162513.514771] schedule+0x46/0xf0 [162513.514844] wait_current_trans+0xde/0x140 [btrfs] [162513.514850] ? finish_wait+0x90/0x90 [162513.514864] start_transaction+0x37c/0x5f0 [btrfs] [162513.514879] transaction_kthread+0xa4/0x170 [btrfs] [162513.514891] ? btrfs_cleanup_transaction+0x660/0x660 [btrfs] [162513.514894] kthread+0x153/0x170 [162513.514897] ? kthread_stop+0x2c0/0x2c0 [162513.514902] ret_from_fork+0x22/0x30 [162513.514916] INFO: task fsstress:1356184 blocked for more than 120 seconds. [162513.515192] Not tainted 5.9.0-rc6-btrfs-next-69 #1 [162513.515431] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [162513.515680] task:fsstress state:D stack: 0 pid:1356184 ppid:1356177 flags:0x00004000 [162513.515682] Call Trace: [162513.515688] __schedule+0x5ce/0xd00 [162513.515691] ? _raw_spin_unlock_irqrestore+0x3c/0x60 [162513.515697] schedule+0x46/0xf0 [162513.515712] wait_current_trans+0xde/0x140 [btrfs] [162513.515716] ? finish_wait+0x90/0x90 [162513.515729] start_transaction+0x37c/0x5f0 [btrfs] [162513.515743] btrfs_attach_transaction_barrier+0x1f/0x50 [btrfs] [162513.515753] btrfs_sync_fs+0x61/0x1c0 [btrfs] [162513.515758] ? __ia32_sys_fdatasync+0x20/0x20 [162513.515761] iterate_supers+0x87/0xf0 [162513.515765] ksys_sync+0x60/0xb0 [162513.515768] __do_sys_sync+0xa/0x10 [162513.515771] do_syscall_64+0x33/0x80 [162513.515774] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [162513.515781] RIP: 0033:0x7f5238f50bd7 [162513.515782] Code: Bad RIP value. [162513.515784] RSP: 002b:00007fff67b978e8 EFLAGS: 00000206 ORIG_RAX: 00000000000000a2 [162513.515786] RAX: ffffffffffffffda RBX: 000055b1fad2c560 RCX: 00007f5238f50bd7 [162513.515788] RDX: 00000000ffffffff RSI: 000000000daf0e74 RDI: 000000000000003a [162513.515789] RBP: 0000000000000032 R08: 000000000000000a R09: 00007f5239019be0 [162513.515791] R10: fffffffffffff24f R11: 0000000000000206 R12: 000000000000003a [162513.515792] R13: 00007fff67b97950 R14: 00007fff67b97906 R15: 000055b1fad1a340 [162513.515804] INFO: task fsstress:1356185 blocked for more than 120 seconds. [162513.516064] Not tainted 5.9.0-rc6-btrfs-next-69 #1 [162513.516329] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [162513.516617] task:fsstress state:D stack: 0 pid:1356185 ppid:1356177 flags:0x00000000 [162513.516620] Call Trace: [162513.516625] __schedule+0x5ce/0xd00 [162513.516628] ? _raw_spin_unlock_irqrestore+0x3c/0x60 [162513.516634] schedule+0x46/0xf0 [162513.516647] wait_current_trans+0xde/0x140 [btrfs] [162513.516650] ? finish_wait+0x90/0x90 [162513.516662] start_transaction+0x4d7/0x5f0 [btrfs] [162513.516679] btrfs_setxattr_trans+0x3c/0x100 [btrfs] [162513.516686] __vfs_setxattr+0x66/0x80 [162513.516691] __vfs_setxattr_noperm+0x70/0x200 [162513.516697] vfs_setxattr+0x6b/0x120 [162513.516703] setxattr+0x125/0x240 [162513.516709] ? lock_acquire+0xb1/0x480 [162513.516712] ? mnt_want_write+0x20/0x50 [162513.516721] ? rcu_read_lock_any_held+0x8e/0xb0 [162513.516723] ? preempt_count_add+0x49/0xa0 [162513.516725] ? __sb_start_write+0x19b/0x290 [162513.516727] ? preempt_count_add+0x49/0xa0 [162513.516732] path_setxattr+0xba/0xd0 [162513.516739] __x64_sys_setxattr+0x27/0x30 [162513.516741] do_syscall_64+0x33/0x80 [162513.516743] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [162513.516745] RIP: 0033:0x7f5238f56d5a [162513.516746] Code: Bad RIP value. [162513.516748] RSP: 002b:00007fff67b97868 EFLAGS: 00000202 ORIG_RAX: 00000000000000bc [162513.516750] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f5238f56d5a [162513.516751] RDX: 000055b1fbb0d5a0 RSI: 00007fff67b978a0 RDI: 000055b1fbb0d470 [162513.516753] RBP: 000055b1fbb0d5a0 R08: 0000000000000001 R09: 00007fff67b97700 [162513.516754] R10: 0000000000000004 R11: 0000000000000202 R12: 0000000000000004 [162513.516756] R13: 0000000000000024 R14: 0000000000000001 R15: 00007fff67b978a0 [162513.516767] INFO: task fsstress:1356196 blocked for more than 120 seconds. [162513.517064] Not tainted 5.9.0-rc6-btrfs-next-69 #1 [162513.517365] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [162513.517763] task:fsstress state:D stack: 0 pid:1356196 ppid:1356177 flags:0x00004000 [162513.517780] Call Trace: [162513.517786] __schedule+0x5ce/0xd00 [162513.517789] ? _raw_spin_unlock_irqrestore+0x3c/0x60 [162513.517796] schedule+0x46/0xf0 [162513.517810] wait_current_trans+0xde/0x140 [btrfs] [162513.517814] ? finish_wait+0x90/0x90 [162513.517829] start_transaction+0x37c/0x5f0 [btrfs] [162513.517845] btrfs_attach_transaction_barrier+0x1f/0x50 [btrfs] [162513.517857] btrfs_sync_fs+0x61/0x1c0 [btrfs] [162513.517862] ? __ia32_sys_fdatasync+0x20/0x20 [162513.517865] iterate_supers+0x87/0xf0 [162513.517869] ksys_sync+0x60/0xb0 [162513.517872] __do_sys_sync+0xa/0x10 [162513.517875] do_syscall_64+0x33/0x80 [162513.517878] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [162513.517881] RIP: 0033:0x7f5238f50bd7 [162513.517883] Code: Bad RIP value. [162513.517885] RSP: 002b:00007fff67b978e8 EFLAGS: 00000206 ORIG_RAX: 00000000000000a2 [162513.517887] RAX: ffffffffffffffda RBX: 000055b1fad2c560 RCX: 00007f5238f50bd7 [162513.517889] RDX: 0000000000000000 RSI: 000000007660add2 RDI: 0000000000000053 [162513.517891] RBP: 0000000000000032 R08: 0000000000000067 R09: 00007f5239019be0 [162513.517893] R10: fffffffffffff24f R11: 0000000000000206 R12: 0000000000000053 [162513.517895] R13: 00007fff67b97950 R14: 00007fff67b97906 R15: 000055b1fad1a340 [162513.517908] INFO: task fsstress:1356197 blocked for more than 120 seconds. [162513.518298] Not tainted 5.9.0-rc6-btrfs-next-69 #1 [162513.518672] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [162513.519157] task:fsstress state:D stack: 0 pid:1356197 ppid:1356177 flags:0x00000000 [162513.519160] Call Trace: [162513.519165] __schedule+0x5ce/0xd00 [162513.519168] ? _raw_spin_unlock_irqrestore+0x3c/0x60 [162513.519174] schedule+0x46/0xf0 [162513.519190] wait_current_trans+0xde/0x140 [btrfs] [162513.519193] ? finish_wait+0x90/0x90 [162513.519206] start_transaction+0x4d7/0x5f0 [btrfs] [162513.519222] btrfs_create+0x57/0x200 [btrfs] [162513.519230] lookup_open+0x522/0x650 [162513.519246] path_openat+0x2b8/0xa50 [162513.519270] do_filp_open+0x91/0x100 [162513.519275] ? find_held_lock+0x32/0x90 [162513.519280] ? lock_acquired+0x33b/0x470 [162513.519285] ? do_raw_spin_unlock+0x4b/0xc0 [162513.519287] ? _raw_spin_unlock+0x29/0x40 [162513.519295] do_sys_openat2+0x20d/0x2d0 [162513.519300] do_sys_open+0x44/0x80 [162513.519304] do_syscall_64+0x33/0x80 [162513.519307] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [162513.519309] RIP: 0033:0x7f5238f4a903 [162513.519310] Code: Bad RIP value. [162513.519312] RSP: 002b:00007fff67b97758 EFLAGS: 00000246 ORIG_RAX: 0000000000000055 [162513.519314] RAX: ffffffffffffffda RBX: 00000000ffffffff RCX: 00007f5238f4a903 [162513.519316] RDX: 0000000000000000 RSI: 00000000000001b6 RDI: 000055b1fbb0d470 [162513.519317] RBP: 00007fff67b978c0 R08: 0000000000000001 R09: 0000000000000002 [162513.519319] R10: 00007fff67b974f7 R11: 0000000000000246 R12: 0000000000000013 [162513.519320] R13: 00000000000001b6 R14: 00007fff67b97906 R15: 000055b1fad1c620 [162513.519332] INFO: task btrfs:1356211 blocked for more than 120 seconds. [162513.519727] Not tainted 5.9.0-rc6-btrfs-next-69 #1 [162513.520115] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [162513.520508] task:btrfs state:D stack: 0 pid:1356211 ppid:1356178 flags:0x00004002 [162513.520511] Call Trace: [162513.520516] __schedule+0x5ce/0xd00 [162513.520519] ? _raw_spin_unlock_irqrestore+0x3c/0x60 [162513.520525] schedule+0x46/0xf0 [162513.520544] btrfs_scrub_pause+0x11f/0x180 [btrfs] [162513.520548] ? finish_wait+0x90/0x90 [162513.520562] btrfs_commit_transaction+0x45a/0xc30 [btrfs] [162513.520574] ? start_transaction+0xe0/0x5f0 [btrfs] [162513.520596] btrfs_dev_replace_finishing+0x6d8/0x711 [btrfs] [162513.520619] btrfs_dev_replace_by_ioctl.cold+0x1cc/0x1fd [btrfs] [162513.520639] btrfs_ioctl+0x2a25/0x36f0 [btrfs] [162513.520643] ? do_sigaction+0xf3/0x240 [162513.520645] ? find_held_lock+0x32/0x90 [162513.520648] ? do_sigaction+0xf3/0x240 [162513.520651] ? lock_acquired+0x33b/0x470 [162513.520655] ? _raw_spin_unlock_irq+0x24/0x50 [162513.520657] ? lockdep_hardirqs_on+0x7d/0x100 [162513.520660] ? _raw_spin_unlock_irq+0x35/0x50 [162513.520662] ? do_sigaction+0xf3/0x240 [162513.520671] ? __x64_sys_ioctl+0x83/0xb0 [162513.520672] __x64_sys_ioctl+0x83/0xb0 [162513.520677] do_syscall_64+0x33/0x80 [162513.520679] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [162513.520681] RIP: 0033:0x7fc3cd307d87 [162513.520682] Code: Bad RIP value. [162513.520684] RSP: 002b:00007ffe30a56bb8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 [162513.520686] RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007fc3cd307d87 [162513.520687] RDX: 00007ffe30a57a30 RSI: 00000000ca289435 RDI: 0000000000000003 [162513.520689] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [162513.520690] R10: 0000000000000008 R11: 0000000000000202 R12: 0000000000000003 [162513.520692] R13: 0000557323a212e0 R14: 00007ffe30a5a520 R15: 0000000000000001 [162513.520703] Showing all locks held in the system: [162513.520712] 1 lock held by khungtaskd/54: [162513.520713] #0: ffffffffb40a91a0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x15/0x197 [162513.520728] 1 lock held by in:imklog/596: [162513.520729] #0: ffff8f3f0d781400 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x4d/0x60 [162513.520782] 1 lock held by btrfs-transacti/1356167: [162513.520784] #0: ffff8f3d810cc848 (&fs_info->transaction_kthread_mutex){+.+.}-{3:3}, at: transaction_kthread+0x4a/0x170 [btrfs] [162513.520798] 1 lock held by btrfs/1356190: [162513.520800] #0: ffff8f3d57644470 (sb_writers#15){.+.+}-{0:0}, at: mnt_want_write_file+0x22/0x60 [162513.520805] 1 lock held by fsstress/1356184: [162513.520806] #0: ffff8f3d576440e8 (&type->s_umount_key#62){++++}-{3:3}, at: iterate_supers+0x6f/0xf0 [162513.520811] 3 locks held by fsstress/1356185: [162513.520812] #0: ffff8f3d57644470 (sb_writers#15){.+.+}-{0:0}, at: mnt_want_write+0x20/0x50 [162513.520815] #1: ffff8f3d80a650b8 (&type->i_mutex_dir_key#10){++++}-{3:3}, at: vfs_setxattr+0x50/0x120 [162513.520820] #2: ffff8f3d57644690 (sb_internal#2){.+.+}-{0:0}, at: start_transaction+0x40e/0x5f0 [btrfs] [162513.520833] 1 lock held by fsstress/1356196: [162513.520834] #0: ffff8f3d576440e8 (&type->s_umount_key#62){++++}-{3:3}, at: iterate_supers+0x6f/0xf0 [162513.520838] 3 locks held by fsstress/1356197: [162513.520839] #0: ffff8f3d57644470 (sb_writers#15){.+.+}-{0:0}, at: mnt_want_write+0x20/0x50 [162513.520843] #1: ffff8f3d506465e8 (&type->i_mutex_dir_key#10){++++}-{3:3}, at: path_openat+0x2a7/0xa50 [162513.520846] #2: ffff8f3d57644690 (sb_internal#2){.+.+}-{0:0}, at: start_transaction+0x40e/0x5f0 [btrfs] [162513.520858] 2 locks held by btrfs/1356211: [162513.520859] #0: ffff8f3d810cde30 (&fs_info->dev_replace.lock_finishing_cancel_unmount){+.+.}-{3:3}, at: btrfs_dev_replace_finishing+0x52/0x711 [btrfs] [162513.520877] #1: ffff8f3d57644690 (sb_internal#2){.+.+}-{0:0}, at: start_transaction+0x40e/0x5f0 [btrfs] This was weird because the stack traces show that a transaction commit, triggered by a device replace operation, is blocking trying to pause any running scrubs but there are no stack traces of blocked tasks doing a scrub. After poking around with drgn, I noticed there was a scrub task that was constantly running and blocking for shorts periods of time: >>> t = find_task(prog, 1356190) >>> prog.stack_trace(t) #0 __schedule+0x5ce/0xcfc #1 schedule+0x46/0xe4 #2 schedule_timeout+0x1df/0x475 #3 btrfs_reada_wait+0xda/0x132 #4 scrub_stripe+0x2a8/0x112f #5 scrub_chunk+0xcd/0x134 #6 scrub_enumerate_chunks+0x29e/0x5ee #7 btrfs_scrub_dev+0x2d5/0x91b #8 btrfs_ioctl+0x7f5/0x36e7 #9 __x64_sys_ioctl+0x83/0xb0 #10 do_syscall_64+0x33/0x77 #11 entry_SYSCALL_64+0x7c/0x156 Which corresponds to: int btrfs_reada_wait(void *handle) { struct reada_control *rc = handle; struct btrfs_fs_info *fs_info = rc->fs_info; while (atomic_read(&rc->elems)) { if (!atomic_read(&fs_info->reada_works_cnt)) reada_start_machine(fs_info); wait_event_timeout(rc->wait, atomic_read(&rc->elems) == 0, (HZ + 9) / 10); } (...) So the counter "rc->elems" was set to 1 and never decreased to 0, causing the scrub task to loop forever in that function. Then I used the following script for drgn to check the readahead requests: $ cat dump_reada.py import sys import drgn from drgn import NULL, Object, cast, container_of, execscript, \ reinterpret, sizeof from drgn.helpers.linux import * mnt_path = b"/home/fdmanana/btrfs-tests/scratch_1" mnt = None for mnt in for_each_mount(prog, dst = mnt_path): pass if mnt is None: sys.stderr.write(f'Error: mount point {mnt_path} not found\n') sys.exit(1) fs_info = cast('struct btrfs_fs_info *', mnt.mnt.mnt_sb.s_fs_info) def dump_re(re): nzones = re.nzones.value_() print(f're at {hex(re.value_())}') print(f'\t logical {re.logical.value_()}') print(f'\t refcnt {re.refcnt.value_()}') print(f'\t nzones {nzones}') for i in range(nzones): dev = re.zones[i].device name = dev.name.str.string_() print(f'\t\t dev id {dev.devid.value_()} name {name}') print() for _, e in radix_tree_for_each(fs_info.reada_tree): re = cast('struct reada_extent *', e) dump_re(re) $ drgn dump_reada.py re at 0xffff8f3da9d25ad8 logical 38928384 refcnt 1 nzones 1 dev id 0 name b'/dev/sdd' $ So there was one readahead extent with a single zone corresponding to the source device of that last device replace operation logged in dmesg/syslog. Also the ID of that zone's device was 0 which is a special value set in the source device of a device replace operation when the operation finishes (constant BTRFS_DEV_REPLACE_DEVID set at btrfs_dev_replace_finishing()), confirming again that device /dev/sdd was the source of a device replace operation. Normally there should be as many zones in the readahead extent as there are devices, and I wasn't expecting the extent to be in a block group with a 'single' profile, so I went and confirmed with the following drgn script that there weren't any single profile block groups: $ cat dump_block_groups.py import sys import drgn from drgn import NULL, Object, cast, container_of, execscript, \ reinterpret, sizeof from drgn.helpers.linux import * mnt_path = b"/home/fdmanana/btrfs-tests/scratch_1" mnt = None for mnt in for_each_mount(prog, dst = mnt_path): pass if mnt is None: sys.stderr.write(f'Error: mount point {mnt_path} not found\n') sys.exit(1) fs_info = cast('struct btrfs_fs_info *', mnt.mnt.mnt_sb.s_fs_info) BTRFS_BLOCK_GROUP_DATA = (1 << 0) BTRFS_BLOCK_GROUP_SYSTEM = (1 << 1) BTRFS_BLOCK_GROUP_METADATA = (1 << 2) BTRFS_BLOCK_GROUP_RAID0 = (1 << 3) BTRFS_BLOCK_GROUP_RAID1 = (1 << 4) BTRFS_BLOCK_GROUP_DUP = (1 << 5) BTRFS_BLOCK_GROUP_RAID10 = (1 << 6) BTRFS_BLOCK_GROUP_RAID5 = (1 << 7) BTRFS_BLOCK_GROUP_RAID6 = (1 << 8) BTRFS_BLOCK_GROUP_RAID1C3 = (1 << 9) BTRFS_BLOCK_GROUP_RAID1C4 = (1 << 10) def bg_flags_string(bg): flags = bg.flags.value_() ret = '' if flags & BTRFS_BLOCK_GROUP_DATA: ret = 'data' if flags & BTRFS_BLOCK_GROUP_METADATA: if len(ret) > 0: ret += '|' ret += 'meta' if flags & BTRFS_BLOCK_GROUP_SYSTEM: if len(ret) > 0: ret += '|' ret += 'system' if flags & BTRFS_BLOCK_GROUP_RAID0: ret += ' raid0' elif flags & BTRFS_BLOCK_GROUP_RAID1: ret += ' raid1' elif flags & BTRFS_BLOCK_GROUP_DUP: ret += ' dup' elif flags & BTRFS_BLOCK_GROUP_RAID10: ret += ' raid10' elif flags & BTRFS_BLOCK_GROUP_RAID5: ret += ' raid5' elif flags & BTRFS_BLOCK_GROUP_RAID6: ret += ' raid6' elif flags & BTRFS_BLOCK_GROUP_RAID1C3: ret += ' raid1c3' elif flags & BTRFS_BLOCK_GROUP_RAID1C4: ret += ' raid1c4' else: ret += ' single' return ret def dump_bg(bg): print() print(f'block group at {hex(bg.value_())}') print(f'\t start {bg.start.value_()} length {bg.length.value_()}') print(f'\t flags {bg.flags.value_()} - {bg_flags_string(bg)}') bg_root = fs_info.block_group_cache_tree.address_of_() for bg in rbtree_inorder_for_each_entry('struct btrfs_block_group', bg_root, 'cache_node'): dump_bg(bg) $ drgn dump_block_groups.py block group at 0xffff8f3d673b0400 start 22020096 length 16777216 flags 258 - system raid6 block group at 0xffff8f3d53ddb400 start 38797312 length 536870912 flags 260 - meta raid6 block group at 0xffff8f3d5f4d9c00 start 575668224 length 2147483648 flags 257 - data raid6 block group at 0xffff8f3d08189000 start 2723151872 length 67108864 flags 258 - system raid6 block group at 0xffff8f3db70ff000 start 2790260736 length 1073741824 flags 260 - meta raid6 block group at 0xffff8f3d5f4dd800 start 3864002560 length 67108864 flags 258 - system raid6 block group at 0xffff8f3d67037000 start 3931111424 length 2147483648 flags 257 - data raid6 $ So there were only 2 reasons left for having a readahead extent with a single zone: reada_find_zone(), called when creating a readahead extent, returned NULL either because we failed to find the corresponding block group or because a memory allocation failed. With some additional and custom tracing I figured out that on every further ocurrence of the problem the block group had just been deleted when we were looping to create the zones for the readahead extent (at reada_find_extent()), so we ended up with only one zone in the readahead extent, corresponding to a device that ends up getting replaced. So after figuring that out it became obvious why the hang happens: 1) Task A starts a scrub on any device of the filesystem, except for device /dev/sdd; 2) Task B starts a device replace with /dev/sdd as the source device; 3) Task A calls btrfs_reada_add() from scrub_stripe() and it is currently starting to scrub a stripe from block group X. This call to btrfs_reada_add() is the one for the extent tree. When btrfs_reada_add() calls reada_add_block(), it passes the logical address of the extent tree's root node as its 'logical' argument - a value of 38928384; 4) Task A then enters reada_find_extent(), called from reada_add_block(). It finds there isn't any existing readahead extent for the logical address 38928384, so it proceeds to the path of creating a new one. It calls btrfs_map_block() to find out which stripes exist for the block group X. On the first iteration of the for loop that iterates over the stripes, it finds the stripe for device /dev/sdd, so it creates one zone for that device and adds it to the readahead extent. Before getting into the second iteration of the loop, the cleanup kthread deletes block group X because it was empty. So in the iterations for the remaining stripes it does not add more zones to the readahead extent, because the calls to reada_find_zone() returned NULL because they couldn't find block group X anymore. As a result the new readahead extent has a single zone, corresponding to the device /dev/sdd; 4) Before task A returns to btrfs_reada_add() and queues the readahead job for the readahead work queue, task B finishes the device replace and at btrfs_dev_replace_finishing() swaps the device /dev/sdd with the new device /dev/sdg; 5) Task A returns to reada_add_block(), which increments the counter "->elems" of the reada_control structure allocated at btrfs_reada_add(). Then it returns back to btrfs_reada_add() and calls reada_start_machine(). This queues a job in the readahead work queue to run the function reada_start_machine_worker(), which calls __reada_start_machine(). At __reada_start_machine() we take the device list mutex and for each device found in the current device list, we call reada_start_machine_dev() to start the readahead work. However at this point the device /dev/sdd was already freed and is not in the device list anymore. This means the corresponding readahead for the extent at 38928384 is never started, and therefore the "->elems" counter of the reada_control structure allocated at btrfs_reada_add() never goes down to 0, causing the call to btrfs_reada_wait(), done by the scrub task, to wait forever. Note that the readahead request can be made either after the device replace started or before it started, however in pratice it is very unlikely that a device replace is able to start after a readahead request is made and is able to complete before the readahead request completes - maybe only on a very small and nearly empty filesystem. This hang however is not the only problem we can have with readahead and device removals. When the readahead extent has other zones other than the one corresponding to the device that is being removed (either by a device replace or a device remove operation), we risk having a use-after-free on the device when dropping the last reference of the readahead extent. For example if we create a readahead extent with two zones, one for the device /dev/sdd and one for the device /dev/sde: 1) Before the readahead worker starts, the device /dev/sdd is removed, and the corresponding btrfs_device structure is freed. However the readahead extent still has the zone pointing to the device structure; 2) When the readahead worker starts, it only finds device /dev/sde in the current device list of the filesystem; 3) It starts the readahead work, at reada_start_machine_dev(), using the device /dev/sde; 4) Then when it finishes reading the extent from device /dev/sde, it calls __readahead_hook() which ends up dropping the last reference on the readahead extent through the last call to reada_extent_put(); 5) At reada_extent_put() it iterates over each zone of the readahead extent and attempts to delete an element from the device's 'reada_extents' radix tree, resulting in a use-after-free, as the device pointer of the zone for /dev/sdd is now stale. We can also access the device after dropping the last reference of a zone, through reada_zone_release(), also called by reada_extent_put(). And a device remove suffers the same problem, however since it shrinks the device size down to zero before removing the device, it is very unlikely to still have readahead requests not completed by the time we free the device, the only possibility is if the device has a very little space allocated. While the hang problem is exclusive to scrub, since it is currently the only user of btrfs_reada_add() and btrfs_reada_wait(), the use-after-free problem affects any path that triggers readhead, which includes btree_readahead_hook() and __readahead_hook() (a readahead worker can trigger readahed for the children of a node) for example - any path that ends up calling reada_add_block() can trigger the use-after-free after a device is removed. So fix this by waiting for any readahead requests for a device to complete before removing a device, ensuring that while waiting for existing ones no new ones can be made. This problem has been around for a very long time - the readahead code was added in 2011, device remove exists since 2008 and device replace was introduced in 2013, hard to pick a specific commit for a git Fixes tag. CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>

When enabling qgroups we walk the tree_root and then add a qgroup item for every root that we have. This creates a lock dependency on the tree_root and qgroup_root, which results in the following lockdep splat (with tree locks using rwsem), eg. in tests btrfs/017 or btrfs/022: ====================================================== WARNING: possible circular locking dependency detected 5.9.0-default+ #1299 Not tainted ------------------------------------------------------ btrfs/24552 is trying to acquire lock: ffff9142dfc5f630 (btrfs-quota-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x35/0x1c0 [btrfs] but task is already holding lock: ffff9142dfc5d0b0 (btrfs-root-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x35/0x1c0 [btrfs] which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (btrfs-root-00){++++}-{3:3}: __lock_acquire+0x3fb/0x730 lock_acquire.part.0+0x6a/0x130 down_read_nested+0x46/0x130 __btrfs_tree_read_lock+0x35/0x1c0 [btrfs] __btrfs_read_lock_root_node+0x3a/0x50 [btrfs] btrfs_search_slot_get_root+0x11d/0x290 [btrfs] btrfs_search_slot+0xc3/0x9f0 [btrfs] btrfs_insert_item+0x6e/0x140 [btrfs] btrfs_create_tree+0x1cb/0x240 [btrfs] btrfs_quota_enable+0xcd/0x790 [btrfs] btrfs_ioctl_quota_ctl+0xc9/0xe0 [btrfs] __x64_sys_ioctl+0x83/0xa0 do_syscall_64+0x2d/0x70 entry_SYSCALL_64_after_hwframe+0x44/0xa9 -> #0 (btrfs-quota-00){++++}-{3:3}: check_prev_add+0x91/0xc30 validate_chain+0x491/0x750 __lock_acquire+0x3fb/0x730 lock_acquire.part.0+0x6a/0x130 down_read_nested+0x46/0x130 __btrfs_tree_read_lock+0x35/0x1c0 [btrfs] __btrfs_read_lock_root_node+0x3a/0x50 [btrfs] btrfs_search_slot_get_root+0x11d/0x290 [btrfs] btrfs_search_slot+0xc3/0x9f0 [btrfs] btrfs_insert_empty_items+0x58/0xa0 [btrfs] add_qgroup_item.part.0+0x72/0x210 [btrfs] btrfs_quota_enable+0x3bb/0x790 [btrfs] btrfs_ioctl_quota_ctl+0xc9/0xe0 [btrfs] __x64_sys_ioctl+0x83/0xa0 do_syscall_64+0x2d/0x70 entry_SYSCALL_64_after_hwframe+0x44/0xa9 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(btrfs-root-00); lock(btrfs-quota-00); lock(btrfs-root-00); lock(btrfs-quota-00); *** DEADLOCK *** 5 locks held by btrfs/24552: #0: ffff9142df431478 (sb_writers#10){.+.+}-{0:0}, at: mnt_want_write_file+0x22/0xa0 #1: ffff9142f9b10cc0 (&fs_info->subvol_sem){++++}-{3:3}, at: btrfs_ioctl_quota_ctl+0x7b/0xe0 [btrfs] #2: ffff9142f9b11a08 (&fs_info->qgroup_ioctl_lock){+.+.}-{3:3}, at: btrfs_quota_enable+0x3b/0x790 [btrfs] #3: ffff9142df431698 (sb_internal#2){.+.+}-{0:0}, at: start_transaction+0x406/0x510 [btrfs] #4: ffff9142dfc5d0b0 (btrfs-root-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x35/0x1c0 [btrfs] stack backtrace: CPU: 1 PID: 24552 Comm: btrfs Not tainted 5.9.0-default+ #1299 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba527-rebuilt.opensuse.org 04/01/2014 Call Trace: dump_stack+0x77/0x97 check_noncircular+0xf3/0x110 check_prev_add+0x91/0xc30 validate_chain+0x491/0x750 __lock_acquire+0x3fb/0x730 lock_acquire.part.0+0x6a/0x130 ? __btrfs_tree_read_lock+0x35/0x1c0 [btrfs] ? lock_acquire+0xc4/0x140 ? __btrfs_tree_read_lock+0x35/0x1c0 [btrfs] down_read_nested+0x46/0x130 ? __btrfs_tree_read_lock+0x35/0x1c0 [btrfs] __btrfs_tree_read_lock+0x35/0x1c0 [btrfs] ? btrfs_root_node+0xd9/0x200 [btrfs] __btrfs_read_lock_root_node+0x3a/0x50 [btrfs] btrfs_search_slot_get_root+0x11d/0x290 [btrfs] btrfs_search_slot+0xc3/0x9f0 [btrfs] btrfs_insert_empty_items+0x58/0xa0 [btrfs] add_qgroup_item.part.0+0x72/0x210 [btrfs] btrfs_quota_enable+0x3bb/0x790 [btrfs] btrfs_ioctl_quota_ctl+0xc9/0xe0 [btrfs] __x64_sys_ioctl+0x83/0xa0 do_syscall_64+0x2d/0x70 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Fix this by dropping the path whenever we find a root item, add the qgroup item, and then re-lookup the root item we found and continue processing roots. Reported-by: David Sterba <dsterba@suse.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>

This fix is for a failure that occurred in the DWARF unwind perf test. Stack unwinders may probe memory when looking for frames. Memory sanitizer will poison and track uninitialized memory on the stack, and on the heap if the value is copied to the heap. This can lead to false memory sanitizer failures for the use of an uninitialized value. Avoid this problem by removing the poison on the copied stack. The full msan failure with track origins looks like: ==2168==WARNING: MemorySanitizer: use-of-uninitialized-value #0 0x559ceb10755b in handle_cfi elfutils/libdwfl/frame_unwind.c:648:8 #1 0x559ceb105448 in __libdwfl_frame_unwind elfutils/libdwfl/frame_unwind.c:741:4 #2 0x559ceb0ece90 in dwfl_thread_getframes elfutils/libdwfl/dwfl_frame.c:435:7 #3 0x559ceb0ec6b7 in get_one_thread_frames_cb elfutils/libdwfl/dwfl_frame.c:379:10 #4 0x559ceb0ec6b7 in get_one_thread_cb elfutils/libdwfl/dwfl_frame.c:308:17 #5 0x559ceb0ec6b7 in dwfl_getthreads elfutils/libdwfl/dwfl_frame.c:283:17 #6 0x559ceb0ec6b7 in getthread elfutils/libdwfl/dwfl_frame.c:354:14 #7 0x559ceb0ec6b7 in dwfl_getthread_frames elfutils/libdwfl/dwfl_frame.c:388:10 #8 0x559ceaff6ae6 in unwind__get_entries tools/perf/util/unwind-libdw.c:236:8 #9 0x559ceabc9dbc in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:111:8 #10 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26 #11 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0) #12 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2 #13 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9 #14 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9 #15 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8 #16 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9 #17 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9 #18 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4 #19 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9 #20 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11 #21 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8 #22 0x559cea95fbce in run_argv tools/perf/perf.c:409:2 #23 0x559cea95fbce in main tools/perf/perf.c:539:3 Uninitialized value was stored to memory at #0 0x559ceb106acf in __libdwfl_frame_reg_set elfutils/libdwfl/frame_unwind.c:77:22 #1 0x559ceb106acf in handle_cfi elfutils/libdwfl/frame_unwind.c:627:13 #2 0x559ceb105448 in __libdwfl_frame_unwind elfutils/libdwfl/frame_unwind.c:741:4 #3 0x559ceb0ece90 in dwfl_thread_getframes elfutils/libdwfl/dwfl_frame.c:435:7 #4 0x559ceb0ec6b7 in get_one_thread_frames_cb elfutils/libdwfl/dwfl_frame.c:379:10 #5 0x559ceb0ec6b7 in get_one_thread_cb elfutils/libdwfl/dwfl_frame.c:308:17 #6 0x559ceb0ec6b7 in dwfl_getthreads elfutils/libdwfl/dwfl_frame.c:283:17 #7 0x559ceb0ec6b7 in getthread elfutils/libdwfl/dwfl_frame.c:354:14 #8 0x559ceb0ec6b7 in dwfl_getthread_frames elfutils/libdwfl/dwfl_frame.c:388:10 #9 0x559ceaff6ae6 in unwind__get_entries tools/perf/util/unwind-libdw.c:236:8 #10 0x559ceabc9dbc in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:111:8 #11 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26 #12 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0) #13 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2 #14 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9 #15 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9 #16 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8 #17 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9 #18 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9 #19 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4 #20 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9 #21 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11 #22 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8 #23 0x559cea95fbce in run_argv tools/perf/perf.c:409:2 #24 0x559cea95fbce in main tools/perf/perf.c:539:3 Uninitialized value was stored to memory at #0 0x559ceb106a54 in handle_cfi elfutils/libdwfl/frame_unwind.c:613:9 #1 0x559ceb105448 in __libdwfl_frame_unwind elfutils/libdwfl/frame_unwind.c:741:4 #2 0x559ceb0ece90 in dwfl_thread_getframes elfutils/libdwfl/dwfl_frame.c:435:7 #3 0x559ceb0ec6b7 in get_one_thread_frames_cb elfutils/libdwfl/dwfl_frame.c:379:10 #4 0x559ceb0ec6b7 in get_one_thread_cb elfutils/libdwfl/dwfl_frame.c:308:17 #5 0x559ceb0ec6b7 in dwfl_getthreads elfutils/libdwfl/dwfl_frame.c:283:17 #6 0x559ceb0ec6b7 in getthread elfutils/libdwfl/dwfl_frame.c:354:14 #7 0x559ceb0ec6b7 in dwfl_getthread_frames elfutils/libdwfl/dwfl_frame.c:388:10 #8 0x559ceaff6ae6 in unwind__get_entries tools/perf/util/unwind-libdw.c:236:8 #9 0x559ceabc9dbc in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:111:8 #10 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26 #11 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0) #12 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2 #13 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9 #14 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9 #15 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8 #16 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9 #17 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9 #18 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4 #19 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9 #20 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11 #21 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8 #22 0x559cea95fbce in run_argv tools/perf/perf.c:409:2 #23 0x559cea95fbce in main tools/perf/perf.c:539:3 Uninitialized value was stored to memory at #0 0x559ceaff8800 in memory_read tools/perf/util/unwind-libdw.c:156:10 #1 0x559ceb10f053 in expr_eval elfutils/libdwfl/frame_unwind.c:501:13 #2 0x559ceb1060cc in handle_cfi elfutils/libdwfl/frame_unwind.c:603:18 #3 0x559ceb105448 in __libdwfl_frame_unwind elfutils/libdwfl/frame_unwind.c:741:4 #4 0x559ceb0ece90 in dwfl_thread_getframes elfutils/libdwfl/dwfl_frame.c:435:7 #5 0x559ceb0ec6b7 in get_one_thread_frames_cb elfutils/libdwfl/dwfl_frame.c:379:10 #6 0x559ceb0ec6b7 in get_one_thread_cb elfutils/libdwfl/dwfl_frame.c:308:17 #7 0x559ceb0ec6b7 in dwfl_getthreads elfutils/libdwfl/dwfl_frame.c:283:17 #8 0x559ceb0ec6b7 in getthread elfutils/libdwfl/dwfl_frame.c:354:14 #9 0x559ceb0ec6b7 in dwfl_getthread_frames elfutils/libdwfl/dwfl_frame.c:388:10 #10 0x559ceaff6ae6 in unwind__get_entries tools/perf/util/unwind-libdw.c:236:8 #11 0x559ceabc9dbc in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:111:8 #12 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26 #13 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0) #14 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2 #15 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9 #16 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9 #17 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8 #18 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9 #19 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9 #20 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4 #21 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9 #22 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11 #23 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8 #24 0x559cea95fbce in run_argv tools/perf/perf.c:409:2 #25 0x559cea95fbce in main tools/perf/perf.c:539:3 Uninitialized value was stored to memory at #0 0x559cea9027d9 in __msan_memcpy llvm/llvm-project/compiler-rt/lib/msan/msan_interceptors.cpp:1558:3 #1 0x559cea9d2185 in sample_ustack tools/perf/arch/x86/tests/dwarf-unwind.c:41:2 #2 0x559cea9d202c in test__arch_unwind_sample tools/perf/arch/x86/tests/dwarf-unwind.c:72:9 #3 0x559ceabc9cbd in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:106:6 #4 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26 #5 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0) #6 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2 #7 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9 #8 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9 #9 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8 #10 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9 #11 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9 #12 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4 #13 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9 #14 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11 #15 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8 #16 0x559cea95fbce in run_argv tools/perf/perf.c:409:2 #17 0x559cea95fbce in main tools/perf/perf.c:539:3 Uninitialized value was created by an allocation of 'bf' in the stack frame of function 'perf_event__synthesize_mmap_events' #0 0x559ceafc5f60 in perf_event__synthesize_mmap_events tools/perf/util/synthetic-events.c:445 SUMMARY: MemorySanitizer: use-of-uninitialized-value elfutils/libdwfl/frame_unwind.c:648:8 in handle_cfi Signed-off-by: Ian Rogers <irogers@google.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: clang-built-linux@googlegroups.com Cc: Jiri Olsa <jolsa@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sandeep Dasgupta <sdasgup@google.com> Cc: Stephane Eranian <eranian@google.com> Link: http://lore.kernel.org/lkml/20201113182053.754625-1-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Actually, burst size is equal to '1 << desc->rqcfg.brst_size'. we should use burst size, not desc->rqcfg.brst_size. dma memcpy performance on Rockchip RV1126 @ 1512MHz A7, 1056MHz LPDDR3, 200MHz DMA: dmatest: /# echo dma0chan0 > /sys/module/dmatest/parameters/channel /# echo 4194304 > /sys/module/dmatest/parameters/test_buf_size /# echo 8 > /sys/module/dmatest/parameters/iterations /# echo y > /sys/module/dmatest/parameters/norandom /# echo y > /sys/module/dmatest/parameters/verbose /# echo 1 > /sys/module/dmatest/parameters/run dmatest: dma0chan0-copy0: result #1: 'test passed' with src_off=0x0 dst_off=0x0 len=0x400000 dmatest: dma0chan0-copy0: result #2: 'test passed' with src_off=0x0 dst_off=0x0 len=0x400000 dmatest: dma0chan0-copy0: result #3: 'test passed' with src_off=0x0 dst_off=0x0 len=0x400000 dmatest: dma0chan0-copy0: result #4: 'test passed' with src_off=0x0 dst_off=0x0 len=0x400000 dmatest: dma0chan0-copy0: result #5: 'test passed' with src_off=0x0 dst_off=0x0 len=0x400000 dmatest: dma0chan0-copy0: result #6: 'test passed' with src_off=0x0 dst_off=0x0 len=0x400000 dmatest: dma0chan0-copy0: result #7: 'test passed' with src_off=0x0 dst_off=0x0 len=0x400000 dmatest: dma0chan0-copy0: result #8: 'test passed' with src_off=0x0 dst_off=0x0 len=0x400000 Before: dmatest: dma0chan0-copy0: summary 8 tests, 0 failures 48 iops 200338 KB/s (0) After this patch: dmatest: dma0chan0-copy0: summary 8 tests, 0 failures 179 iops 734873 KB/s (0) After this patch and increase dma clk to 400MHz: dmatest: dma0chan0-copy0: summary 8 tests, 0 failures 259 iops 1062929 KB/s (0) Signed-off-by: Sugar Zhang <sugar.zhang@rock-chips.com> Link: https://lore.kernel.org/r/1605326106-55681-1-git-send-email-sugar.zhang@rock-chips.com Signed-off-by: Vinod Koul <vkoul@kernel.org>

When requeueing all requests on the device request queue to the blocklayer we might get to an ERP (error recovery) request that is a copy of an original CQR. Those requests do not have blocklayer request information or a pointer to the dasd_queue set. When trying to access those data it will lead to a null pointer dereference in dasd_requeue_all_requests(). Fix by checking if the request is an ERP request that can simply be ignored. The blocklayer request will be requeued by the original CQR that is on the device queue right behind the ERP request. Fixes: 9487cfd ("s390/dasd: fix handling of internal requests") Cc: <stable@vger.kernel.org> #4.16 Signed-off-by: Stefan Haberland <sth@linux.ibm.com> Reviewed-by: Jan Hoeppner <hoeppner@linux.ibm.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>

…/kernel/git/kvmarm/kvmarm into kvm-master KVM/arm64 fixes for v5.10, take #4 - Fix alignment of the new HYP sections - Fix GICR_TYPER access from userspace

adapter->tx_scrq and adapter->rx_scrq could be NULL if the previous reset did not complete after freeing sub crqs. Check for NULL before dereferencing them. Snippet of call trace: ibmvnic 30000006 env6: Releasing sub-CRQ ibmvnic 30000006 env6: Releasing CRQ ... ibmvnic 30000006 env6: Got Control IP offload Response ibmvnic 30000006 env6: Re-setting tx_scrq[0] BUG: Kernel NULL pointer dereference on read at 0x00000000 Faulting instruction address: 0xc008000003dea7cc Oops: Kernel access of bad area, sig: 11 [#1] LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries Modules linked in: rpadlpar_io rpaphp xt_CHECKSUM xt_MASQUERADE xt_conntrack ipt_REJECT nf_reject_ipv4 nft_compat nft_counter nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nf_tables xsk_diag tcp_diag udp_diag raw_diag inet_diag unix_diag af_packet_diag netlink_diag tun bridge stp llc rfkill sunrpc pseries_rng xts vmx_crypto uio_pdrv_genirq uio binfmt_misc ip_tables xfs libcrc32c sd_mod t10_pi sg ibmvscsi ibmvnic ibmveth scsi_transport_srp dm_mirror dm_region_hash dm_log dm_mod CPU: 80 PID: 1856 Comm: kworker/80:2 Tainted: G W 5.8.0+ #4 Workqueue: events __ibmvnic_reset [ibmvnic] NIP: c008000003dea7cc LR: c008000003dea7bc CTR: 0000000000000000 REGS: c0000007ef7db860 TRAP: 0380 Tainted: G W (5.8.0+) MSR: 800000000280b033 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE> CR: 28002422 XER: 0000000d CFAR: c000000000bd9520 IRQMASK: 0 GPR00: c008000003dea7bc c0000007ef7dbaf0 c008000003df7400 c0000007fa26ec00 GPR04: c0000007fcd0d008 c0000007fcd96350 0000000000000027 c0000007fcd0d010 GPR08: 0000000000000023 0000000000000000 0000000000000000 0000000000000000 GPR12: 0000000000002000 c00000001ec18e00 c0000000001982f8 c0000007bad6e840 GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR20: 0000000000000000 0000000000000000 0000000000000000 fffffffffffffef7 GPR24: 0000000000000402 c0000007fa26f3a8 0000000000000003 c00000016f8ec048 GPR28: 0000000000000000 0000000000000000 0000000000000000 c0000007fa26ec00 NIP [c008000003dea7cc] ibmvnic_reset_init+0x15c/0x258 [ibmvnic] LR [c008000003dea7bc] ibmvnic_reset_init+0x14c/0x258 [ibmvnic] Call Trace: [c0000007ef7dbaf0] [c008000003dea7bc] ibmvnic_reset_init+0x14c/0x258 [ibmvnic] (unreliable) [c0000007ef7dbb80] [c008000003de8860] __ibmvnic_reset+0x408/0x970 [ibmvnic] [c0000007ef7dbc50] [c00000000018b7cc] process_one_work+0x2cc/0x800 [c0000007ef7dbd20] [c00000000018bd78] worker_thread+0x78/0x520 [c0000007ef7dbdb0] [c0000000001984c4] kthread+0x1d4/0x1e0 [c0000007ef7dbe20] [c00000000000cea8] ret_from_kernel_thread+0x5c/0x74 Fixes: 57a4943 ("ibmvnic: Reset sub-crqs during driver reset") Signed-off-by: Lijun Pan <ljp@linux.ibm.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>

When executing the LOCK06 locktorture scenario featuring percpu-rwsem, the RCU callback rcu_sync_func() may still be pending after locktorture module is removed. This can in turn lead to the following Oops: BUG: unable to handle page fault for address: ffffffffc00eb920 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 6500a067 P4D 6500a067 PUD 6500c067 PMD 13a36c067 PTE 800000013691c163 Oops: 0000 [#1] PREEMPT SMP CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.9.0-rc5+ #4 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) RIP: 0010:rcu_cblist_dequeue+0x12/0x30 Call Trace: <IRQ> rcu_core+0x1b1/0x860 __do_softirq+0xfe/0x326 asm_call_on_stack+0x12/0x20 </IRQ> do_softirq_own_stack+0x5f/0x80 irq_exit_rcu+0xaf/0xc0 sysvec_apic_timer_interrupt+0x2e/0xb0 asm_sysvec_apic_timer_interrupt+0x12/0x20 This commit avoids tis problem by adding an exit hook in lock_torture_ops and using it to call percpu_free_rwsem() for percpu rwsem torture during the module-cleanup function, thus ensuring that rcu_sync_func() completes before module exits. It is also necessary to call the exit hook if lock_torture_init() fails half-way, so this commit also adds an ->init_called field in lock_torture_cxt to indicate that exit hook, if present, must be called. Signed-off-by: Hou Tao <houtao1@huawei.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

There is no critical section which needs protection with locks while allocating an OPP table, except while adding it to the opp_tables list. And taking the opp_table_lock for the entire duration causes circular dependency issues like the one mentioned below. This patch takes another approach to reduce the size of the critical section to avoid such issues, the details of that are present within the patch. ====================================================== WARNING: possible circular locking dependency detected 5.4.72 #14 Not tainted ------------------------------------------------------ chrome/1865 is trying to acquire lock: ffffffdd34921750 (opp_table_lock){+.+.}, at: _find_opp_table+0x34/0x74 but task is already holding lock: ffffff81f0fc71a8 (reservation_ww_class_mutex){+.+.}, at: submit_lock_objects+0x70/0x1ec fscrypt: AES-256-CTS-CBC using implementation "cts-cbc-aes-ce" which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (reservation_ww_class_mutex){+.+.}: __mutex_lock_common+0xec/0xc0c ww_mutex_lock_interruptible+0x5c/0xc4 msm_gem_fault+0x2c/0x124 __do_fault+0x40/0x16c handle_mm_fault+0x7cc/0xd98 do_page_fault+0x230/0x3b4 do_translation_fault+0x5c/0x78 do_mem_abort+0x4c/0xb4 el0_da+0x1c/0x20 -> #3 (&mm->mmap_sem){++++}: __might_fault+0x70/0x98 compat_filldir+0xf8/0x48c dcache_readdir+0x70/0x1dc iterate_dir+0xd4/0x180 __arm64_compat_sys_getdents+0xa0/0x19c el0_svc_common+0xa8/0x178 el0_svc_compat_handler+0x2c/0x40 el0_svc_compat+0x8/0x10 -> #2 (&sb->s_type->i_mutex_key#3){++++}: down_write+0x54/0x16c start_creating+0x68/0x128 debugfs_create_dir+0x28/0x114 opp_debug_register+0x8c/0xc0 _add_opp_dev_unlocked+0x5c/0x70 _add_opp_dev+0x38/0x58 _opp_get_opp_table+0xdc/0x1ac dev_pm_opp_get_opp_table_indexed+0x24/0x30 dev_pm_opp_of_add_table_indexed+0x48/0x84 of_genpd_add_provider_onecell+0xc0/0x1b8 rpmhpd_probe+0x240/0x268 platform_drv_probe+0x90/0xb0 really_probe+0x134/0x2ec driver_probe_device+0x64/0xfc __device_attach_driver+0x8c/0xa4 bus_for_each_drv+0x90/0xd8 __device_attach+0xc0/0x148 device_initial_probe+0x20/0x2c bus_probe_device+0x34/0x94 device_add+0x1fc/0x3b0 of_device_add+0x3c/0x4c of_platform_device_create_pdata+0xb8/0xfc of_platform_bus_create+0x1e4/0x368 of_platform_populate+0x70/0xbc devm_of_platform_populate+0x58/0xa0 rpmh_rsc_probe+0x36c/0x3cc platform_drv_probe+0x90/0xb0 really_probe+0x134/0x2ec driver_probe_device+0x64/0xfc __device_attach_driver+0x8c/0xa4 bus_for_each_drv+0x90/0xd8 __device_attach+0xc0/0x148 device_initial_probe+0x20/0x2c bus_probe_device+0x34/0x94 device_add+0x1fc/0x3b0 of_device_add+0x3c/0x4c of_platform_device_create_pdata+0xb8/0xfc of_platform_bus_create+0x1e4/0x368 of_platform_bus_create+0x230/0x368 of_platform_populate+0x70/0xbc of_platform_default_populate_init+0xa8/0xc0 do_one_initcall+0x1c8/0x3fc do_initcall_level+0xb4/0x10c do_basic_setup+0x30/0x48 kernel_init_freeable+0x124/0x1a4 kernel_init+0x14/0x104 ret_from_fork+0x10/0x18 -> #1 (&opp_table->lock){+.+.}: __mutex_lock_common+0xec/0xc0c mutex_lock_nested+0x40/0x50 _add_opp_dev+0x2c/0x58 _opp_get_opp_table+0xdc/0x1ac dev_pm_opp_get_opp_table_indexed+0x24/0x30 dev_pm_opp_of_add_table_indexed+0x48/0x84 of_genpd_add_provider_onecell+0xc0/0x1b8 rpmhpd_probe+0x240/0x268 platform_drv_probe+0x90/0xb0 really_probe+0x134/0x2ec driver_probe_device+0x64/0xfc __device_attach_driver+0x8c/0xa4 bus_for_each_drv+0x90/0xd8 __device_attach+0xc0/0x148 device_initial_probe+0x20/0x2c bus_probe_device+0x34/0x94 device_add+0x1fc/0x3b0 of_device_add+0x3c/0x4c of_platform_device_create_pdata+0xb8/0xfc of_platform_bus_create+0x1e4/0x368 of_platform_populate+0x70/0xbc devm_of_platform_populate+0x58/0xa0 rpmh_rsc_probe+0x36c/0x3cc platform_drv_probe+0x90/0xb0 really_probe+0x134/0x2ec driver_probe_device+0x64/0xfc __device_attach_driver+0x8c/0xa4 bus_for_each_drv+0x90/0xd8 __device_attach+0xc0/0x148 device_initial_probe+0x20/0x2c bus_probe_device+0x34/0x94 device_add+0x1fc/0x3b0 of_device_add+0x3c/0x4c of_platform_device_create_pdata+0xb8/0xfc of_platform_bus_create+0x1e4/0x368 of_platform_populate+0x70/0xbc devm_of_platform_populate+0x58/0xa0 rpmh_rsc_probe+0x36c/0x3cc platform_drv_probe+0x90/0xb0 really_probe+0x134/0x2ec driver_probe_device+0x64/0xfc __device_attach_driver+0x8c/0xa4 bus_for_each_drv+0x90/0xd8 __device_attach+0xc0/0x148 device_initial_probe+0x20/0x2c bus_probe_device+0x34/0x94 device_add+0x1fc/0x3b0 of_device_add+0x3c/0x4c of_platform_device_create_pdata+0xb8/0xfc of_platform_bus_create+0x1e4/0x368 of_platform_bus_create+0x230/0x368 of_platform_populate+0x70/0xbc of_platform_default_populate_init+0xa8/0xc0 do_one_initcall+0x1c8/0x3fc do_initcall_level+0xb4/0x10c do_basic_setup+0x30/0x48 kernel_init_freeable+0x124/0x1a4 kernel_init+0x14/0x104 ret_from_fork+0x10/0x18 -> #0 (opp_table_lock){+.+.}: __lock_acquire+0xee4/0x2450 lock_acquire+0x1cc/0x210 __mutex_lock_common+0xec/0xc0c mutex_lock_nested+0x40/0x50 _find_opp_table+0x34/0x74 dev_pm_opp_find_freq_exact+0x2c/0xdc a6xx_gmu_resume+0xc8/0xecc a6xx_pm_resume+0x148/0x200 adreno_resume+0x28/0x34 pm_generic_runtime_resume+0x34/0x48 __rpm_callback+0x70/0x10c rpm_callback+0x34/0x8c rpm_resume+0x414/0x550 __pm_runtime_resume+0x7c/0xa0 msm_gpu_submit+0x60/0x1c0 msm_ioctl_gem_submit+0xadc/0xb60 drm_ioctl_kernel+0x9c/0x118 drm_ioctl+0x27c/0x408 drm_compat_ioctl+0xcc/0xdc __se_compat_sys_ioctl+0x100/0x206c __arm64_compat_sys_ioctl+0x20/0x2c el0_svc_common+0xa8/0x178 el0_svc_compat_handler+0x2c/0x40 el0_svc_compat+0x8/0x10 other info that might help us debug this: Chain exists of: opp_table_lock --> &mm->mmap_sem --> reservation_ww_class_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(reservation_ww_class_mutex); lock(&mm->mmap_sem); lock(reservation_ww_class_mutex); lock(opp_table_lock); *** DEADLOCK *** 3 locks held by chrome/1865: #0: ffffff81edecc0d8 (&dev->struct_mutex){+.+.}, at: msm_ioctl_gem_submit+0x264/0xb60 #1: ffffff81d0000870 (reservation_ww_class_acquire){+.+.}, at: msm_ioctl_gem_submit+0x8e8/0xb60 #2: ffffff81f0fc71a8 (reservation_ww_class_mutex){+.+.}, at: submit_lock_objects+0x70/0x1ec stack backtrace: CPU: 0 PID: 1865 Comm: chrome Not tainted 5.4.72 #14 Hardware name: Google Lazor (rev1+) with LTE (DT) Call trace: dump_backtrace+0x0/0x158 show_stack+0x20/0x2c dump_stack+0xc8/0x160 print_circular_bug+0x2c4/0x2c8 check_noncircular+0x1a8/0x1b0 __lock_acquire+0xee4/0x2450 lock_acquire+0x1cc/0x210 __mutex_lock_common+0xec/0xc0c mutex_lock_nested+0x40/0x50 _find_opp_table+0x34/0x74 dev_pm_opp_find_freq_exact+0x2c/0xdc a6xx_gmu_resume+0xc8/0xecc a6xx_pm_resume+0x148/0x200 adreno_resume+0x28/0x34 pm_generic_runtime_resume+0x34/0x48 __rpm_callback+0x70/0x10c rpm_callback+0x34/0x8c rpm_resume+0x414/0x550 __pm_runtime_resume+0x7c/0xa0 msm_gpu_submit+0x60/0x1c0 msm_ioctl_gem_submit+0xadc/0xb60 drm_ioctl_kernel+0x9c/0x118 drm_ioctl+0x27c/0x408 drm_compat_ioctl+0xcc/0xdc __se_compat_sys_ioctl+0x100/0x206c __arm64_compat_sys_ioctl+0x20/0x2c el0_svc_common+0xa8/0x178 el0_svc_compat_handler+0x2c/0x40 el0_svc_compat+0x8/0x10 Reported-by: Rob Clark <robdclark@gmail.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

Filipe reported the following lockdep splat ====================================================== WARNING: possible circular locking dependency detected 5.10.0-rc2-btrfs-next-71 #1 Not tainted ------------------------------------------------------ find/324157 is trying to acquire lock: ffff8ebc48d293a0 (btrfs-tree-01#2/3){++++}-{3:3}, at: __btrfs_tree_read_lock+0x32/0x1a0 [btrfs] but task is already holding lock: ffff8eb9932c5088 (btrfs-tree-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x32/0x1a0 [btrfs] which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (btrfs-tree-00){++++}-{3:3}: lock_acquire+0xd8/0x490 down_write_nested+0x44/0x120 __btrfs_tree_lock+0x27/0x120 [btrfs] btrfs_search_slot+0x2a3/0xc50 [btrfs] btrfs_insert_empty_items+0x58/0xa0 [btrfs] insert_with_overflow+0x44/0x110 [btrfs] btrfs_insert_xattr_item+0xb8/0x1d0 [btrfs] btrfs_setxattr+0xd6/0x4c0 [btrfs] btrfs_setxattr_trans+0x68/0x100 [btrfs] __vfs_setxattr+0x66/0x80 __vfs_setxattr_noperm+0x70/0x200 vfs_setxattr+0x6b/0x120 setxattr+0x125/0x240 path_setxattr+0xba/0xd0 __x64_sys_setxattr+0x27/0x30 do_syscall_64+0x33/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xa9 -> #0 (btrfs-tree-01#2/3){++++}-{3:3}: check_prev_add+0x91/0xc60 __lock_acquire+0x1689/0x3130 lock_acquire+0xd8/0x490 down_read_nested+0x45/0x220 __btrfs_tree_read_lock+0x32/0x1a0 [btrfs] btrfs_next_old_leaf+0x27d/0x580 [btrfs] btrfs_real_readdir+0x1e3/0x4b0 [btrfs] iterate_dir+0x170/0x1c0 __x64_sys_getdents64+0x83/0x140 do_syscall_64+0x33/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xa9 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(btrfs-tree-00); lock(btrfs-tree-01#2/3); lock(btrfs-tree-00); lock(btrfs-tree-01#2/3); *** DEADLOCK *** 5 locks held by find/324157: #0: ffff8ebc502c6e00 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x4d/0x60 #1: ffff8eb97f689980 (&type->i_mutex_dir_key#10){++++}-{3:3}, at: iterate_dir+0x52/0x1c0 #2: ffff8ebaec00ca58 (btrfs-tree-02#2){++++}-{3:3}, at: __btrfs_tree_read_lock+0x32/0x1a0 [btrfs] #3: ffff8eb98f986f78 (btrfs-tree-01#2){++++}-{3:3}, at: __btrfs_tree_read_lock+0x32/0x1a0 [btrfs] #4: ffff8eb9932c5088 (btrfs-tree-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x32/0x1a0 [btrfs] stack backtrace: CPU: 2 PID: 324157 Comm: find Not tainted 5.10.0-rc2-btrfs-next-71 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 Call Trace: dump_stack+0x8d/0xb5 check_noncircular+0xff/0x110 ? mark_lock.part.0+0x468/0xe90 check_prev_add+0x91/0xc60 __lock_acquire+0x1689/0x3130 ? kvm_clock_read+0x14/0x30 ? kvm_sched_clock_read+0x5/0x10 lock_acquire+0xd8/0x490 ? __btrfs_tree_read_lock+0x32/0x1a0 [btrfs] down_read_nested+0x45/0x220 ? __btrfs_tree_read_lock+0x32/0x1a0 [btrfs] __btrfs_tree_read_lock+0x32/0x1a0 [btrfs] btrfs_next_old_leaf+0x27d/0x580 [btrfs] btrfs_real_readdir+0x1e3/0x4b0 [btrfs] iterate_dir+0x170/0x1c0 __x64_sys_getdents64+0x83/0x140 ? filldir+0x1d0/0x1d0 do_syscall_64+0x33/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xa9 This happens because btrfs_next_old_leaf searches down to our current key, and then walks up the path until we can move to the next slot, and then reads back down the path so we get the next leaf. However it doesn't unlock any lower levels until it replaces them with the new extent buffer. This is technically fine, but of course causes lockdep to complain, because we could be holding locks on lower levels while locking upper levels. Fix this by dropping all nodes below the level that we use as our new starting point before we start reading back down the path. This also allows us to drop the nested/recursive locking magic, because we're no longer locking two nodes at the same level anymore. Reported-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>

If the elem is deleted during be iterated on it, the iteration process will fall into an endless loop. kernel: NMI watchdog: BUG: soft lockup - CPU#4 stuck for 22s! [nfsd:17137] PID: 17137 TASK: ffff8818d93c0000 CPU: 4 COMMAND: "nfsd" [exception RIP: __state_in_grace+76] RIP: ffffffffc00e817c RSP: ffff8818d3aefc98 RFLAGS: 00000246 RAX: ffff881dc0c38298 RBX: ffffffff81b03580 RCX: ffff881dc02c9f50 RDX: ffff881e3fce8500 RSI: 0000000000000001 RDI: ffffffff81b03580 RBP: ffff8818d3aefca0 R8: 0000000000000020 R9: ffff8818d3aefd40 R10: ffff88017fc03800 R11: ffff8818e83933c0 R12: ffff8818d3aefd40 R13: 0000000000000000 R14: ffff8818e8391068 R15: ffff8818fa6e4000 CS: 0010 SS: 0018 #0 [ffff8818d3aefc98] opens_in_grace at ffffffffc00e81e3 [grace] #1 [ffff8818d3aefca8] nfs4_preprocess_stateid_op at ffffffffc02a3e6c [nfsd] #2 [ffff8818d3aefd18] nfsd4_write at ffffffffc028ed5b [nfsd] #3 [ffff8818d3aefd80] nfsd4_proc_compound at ffffffffc0290a0d [nfsd] #4 [ffff8818d3aefdd0] nfsd_dispatch at ffffffffc027b800 [nfsd] #5 [ffff8818d3aefe08] svc_process_common at ffffffffc02017f3 [sunrpc] #6 [ffff8818d3aefe70] svc_process at ffffffffc0201ce3 [sunrpc] #7 [ffff8818d3aefe98] nfsd at ffffffffc027b117 [nfsd] #8 [ffff8818d3aefec8] kthread at ffffffff810b88c1 #9 [ffff8818d3aeff50] ret_from_fork at ffffffff816d1607 The troublemake elem: crash> lock_manager ffff881dc0c38298 struct lock_manager { list = { next = 0xffff881dc0c38298, prev = 0xffff881dc0c38298 }, block_opens = false } Fixes: c87fb4a ("lockd: NLM grace period shouldn't block NFSv4 opens") Signed-off-by: Cheng Lin <cheng.lin130@zte.com.cn> Signed-off-by: Yi Wang <wang.yi59@zte.com.cn> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

A lock dependency loop exists between the root tree lock, the extent tree lock, and the free space tree lock. The root tree lock depends on the free space tree lock because btrfs_create_tree holds the new tree's lock while adding it to the root tree. The extent tree lock depends on the root tree lock because during umount, we write out space cache v1, which writes inodes in the root tree, which results in holding the root tree lock while doing a lookup in the extent tree. Finally, the free space tree depends on the extent tree because populate_free_space_tree holds a locked path in the extent tree and then does a lookup in the free space tree to add the new item. The simplest of the three to break is the one during tree creation: we unlock the leaf before inserting the tree node into the root tree, which fixes the lockdep warning. [30.480136] ====================================================== [30.480830] WARNING: possible circular locking dependency detected [30.481457] 5.9.0-rc8+ #76 Not tainted [30.481897] ------------------------------------------------------ [30.482500] mount/520 is trying to acquire lock: [30.483064] ffff9babebe03908 (btrfs-free-space-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x39/0x180 [30.484054] but task is already holding lock: [30.484637] ffff9babebe24468 (btrfs-extent-01#2){++++}-{3:3}, at: __btrfs_tree_read_lock+0x39/0x180 [30.485581] which lock already depends on the new lock. [30.486397] the existing dependency chain (in reverse order) is: [30.487205] -> #2 (btrfs-extent-01#2){++++}-{3:3}: [30.487825] down_read_nested+0x43/0x150 [30.488306] __btrfs_tree_read_lock+0x39/0x180 [30.488868] __btrfs_read_lock_root_node+0x3a/0x50 [30.489477] btrfs_search_slot+0x464/0x9b0 [30.490009] check_committed_ref+0x59/0x1d0 [30.490603] btrfs_cross_ref_exist+0x65/0xb0 [30.491108] run_delalloc_nocow+0x405/0x930 [30.491651] btrfs_run_delalloc_range+0x60/0x6b0 [30.492203] writepage_delalloc+0xd4/0x150 [30.492688] __extent_writepage+0x18d/0x3a0 [30.493199] extent_write_cache_pages+0x2af/0x450 [30.493743] extent_writepages+0x34/0x70 [30.494231] do_writepages+0x31/0xd0 [30.494642] __filemap_fdatawrite_range+0xad/0xe0 [30.495194] btrfs_fdatawrite_range+0x1b/0x50 [30.495677] __btrfs_write_out_cache+0x40d/0x460 [30.496227] btrfs_write_out_cache+0x8b/0x110 [30.496716] btrfs_start_dirty_block_groups+0x211/0x4e0 [30.497317] btrfs_commit_transaction+0xc0/0xba0 [30.497861] sync_filesystem+0x71/0x90 [30.498303] btrfs_remount+0x81/0x433 [30.498767] reconfigure_super+0x9f/0x210 [30.499261] path_mount+0x9d1/0xa30 [30.499722] do_mount+0x55/0x70 [30.500158] __x64_sys_mount+0xc4/0xe0 [30.500616] do_syscall_64+0x33/0x40 [30.501091] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [30.501629] -> #1 (btrfs-root-00){++++}-{3:3}: [30.502241] down_read_nested+0x43/0x150 [30.502727] __btrfs_tree_read_lock+0x39/0x180 [30.503291] __btrfs_read_lock_root_node+0x3a/0x50 [30.503903] btrfs_search_slot+0x464/0x9b0 [30.504405] btrfs_insert_empty_items+0x60/0xa0 [30.504973] btrfs_insert_item+0x60/0xd0 [30.505412] btrfs_create_tree+0x1b6/0x210 [30.505913] btrfs_create_free_space_tree+0x54/0x110 [30.506460] btrfs_mount_rw+0x15d/0x20f [30.506937] btrfs_remount+0x356/0x433 [30.507369] reconfigure_super+0x9f/0x210 [30.507868] path_mount+0x9d1/0xa30 [30.508264] do_mount+0x55/0x70 [30.508668] __x64_sys_mount+0xc4/0xe0 [30.509186] do_syscall_64+0x33/0x40 [30.509652] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [30.510271] -> #0 (btrfs-free-space-00){++++}-{3:3}: [30.510972] __lock_acquire+0x11ad/0x1b60 [30.511432] lock_acquire+0xa2/0x360 [30.511917] down_read_nested+0x43/0x150 [30.512383] __btrfs_tree_read_lock+0x39/0x180 [30.512947] __btrfs_read_lock_root_node+0x3a/0x50 [30.513455] btrfs_search_slot+0x464/0x9b0 [30.513947] search_free_space_info+0x45/0x90 [30.514465] __add_to_free_space_tree+0x92/0x39d [30.515010] btrfs_create_free_space_tree.cold.22+0x1ee/0x45d [30.515639] btrfs_mount_rw+0x15d/0x20f [30.516142] btrfs_remount+0x356/0x433 [30.516538] reconfigure_super+0x9f/0x210 [30.517065] path_mount+0x9d1/0xa30 [30.517438] do_mount+0x55/0x70 [30.517824] __x64_sys_mount+0xc4/0xe0 [30.518293] do_syscall_64+0x33/0x40 [30.518776] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [30.519335] other info that might help us debug this: [30.520210] Chain exists of: btrfs-free-space-00 --> btrfs-root-00 --> btrfs-extent-01#2 [30.521407] Possible unsafe locking scenario: [30.522037] CPU0 CPU1 [30.522456] ---- ---- [30.522941] lock(btrfs-extent-01#2); [30.523311] lock(btrfs-root-00); [30.523952] lock(btrfs-extent-01#2); [30.524620] lock(btrfs-free-space-00); [30.525068] *** DEADLOCK *** [30.525669] 5 locks held by mount/520: [30.526116] #0: ffff9babebc520e0 (&type->s_umount_key#37){+.+.}-{3:3}, at: path_mount+0x7ef/0xa30 [30.527056] #1: ffff9babebc52640 (sb_internal#2){.+.+}-{0:0}, at: start_transaction+0x3d5/0x5c0 [30.527960] #2: ffff9babeae8f2e8 (&cache->free_space_lock#2){+.+.}-{3:3}, at: btrfs_create_free_space_tree.cold.22+0x101/0x45d [30.529118] #3: ffff9babebe24468 (btrfs-extent-01#2){++++}-{3:3}, at: __btrfs_tree_read_lock+0x39/0x180 [30.530113] #4: ffff9babebd52eb8 (btrfs-extent-00){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x16/0x100 [30.531124] stack backtrace: [30.531528] CPU: 0 PID: 520 Comm: mount Not tainted 5.9.0-rc8+ #76 [30.532166] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.1-4.module_el8.1.0+248+298dec18 04/01/2014 [30.533215] Call Trace: [30.533452] dump_stack+0x8d/0xc0 [30.533797] check_noncircular+0x13c/0x150 [30.534233] __lock_acquire+0x11ad/0x1b60 [30.534667] lock_acquire+0xa2/0x360 [30.535063] ? __btrfs_tree_read_lock+0x39/0x180 [30.535525] down_read_nested+0x43/0x150 [30.535939] ? __btrfs_tree_read_lock+0x39/0x180 [30.536400] __btrfs_tree_read_lock+0x39/0x180 [30.536862] __btrfs_read_lock_root_node+0x3a/0x50 [30.537304] btrfs_search_slot+0x464/0x9b0 [30.537713] ? trace_hardirqs_on+0x1c/0xf0 [30.538148] search_free_space_info+0x45/0x90 [30.538572] __add_to_free_space_tree+0x92/0x39d [30.539071] ? printk+0x48/0x4a [30.539367] btrfs_create_free_space_tree.cold.22+0x1ee/0x45d [30.539972] btrfs_mount_rw+0x15d/0x20f [30.540350] btrfs_remount+0x356/0x433 [30.540773] ? shrink_dcache_sb+0xd9/0x100 [30.541203] reconfigure_super+0x9f/0x210 [30.541642] path_mount+0x9d1/0xa30 [30.542040] do_mount+0x55/0x70 [30.542366] __x64_sys_mount+0xc4/0xe0 [30.542822] do_syscall_64+0x33/0x40 [30.543197] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [30.543691] RIP: 0033:0x7f109f7ab93a [30.546042] RSP: 002b:00007ffc47c4f858 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 [30.546770] RAX: ffffffffffffffda RBX: 00007f109f8cf264 RCX: 00007f109f7ab93a [30.547485] RDX: 0000557e6fc10770 RSI: 0000557e6fc19cf0 RDI: 0000557e6fc19cd0 [30.548185] RBP: 0000557e6fc10520 R08: 0000557e6fc18e30 R09: 0000557e6fc18cb0 [30.548911] R10: 0000000000200020 R11: 0000000000000246 R12: 0000000000000000 [30.549606] R13: 0000557e6fc19cd0 R14: 0000557e6fc10770 R15: 0000557e6fc10520 Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Boris Burkov <boris@bur.io> Signed-off-by: David Sterba <dsterba@suse.com>

The purpose of srv_mutex is to protect srv_list as in put_srv, so no need to hold it when allocate memory for srv since it could be time consuming. Otherwise if one machine has limited memory, rsrv_close_work could be blocked for a longer time due to the mutex is held by get_or_create_srv since it can't get memory in time. INFO: task kworker/1:1:27478 blocked for more than 120 seconds. Tainted: G O 4.14.171-1-storage #4.14.171-1.3~deb9 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/1:1 D 0 27478 2 0x80000000 Workqueue: rtrs_server_wq rtrs_srv_close_work [rtrs_server] Call Trace: ? __schedule+0x38c/0x7e0 schedule+0x32/0x80 schedule_preempt_disabled+0xa/0x10 __mutex_lock.isra.2+0x25e/0x4d0 ? put_srv+0x44/0x100 [rtrs_server] put_srv+0x44/0x100 [rtrs_server] rtrs_srv_close_work+0x16c/0x280 [rtrs_server] process_one_work+0x1c5/0x3c0 worker_thread+0x47/0x3e0 kthread+0xfc/0x130 ? trace_event_raw_event_workqueue_execute_start+0xa0/0xa0 ? kthread_create_on_node+0x70/0x70 ret_from_fork+0x1f/0x30 Let's move all the logics from __find_srv_and_get and __alloc_srv to get_or_create_srv, and remove the two functions. Then it should be safe for multiple processes to access the same srv since it is protected with srv_mutex. And since we don't want to allocate chunks with srv_mutex held, let's check the srv->refcount after get srv because the chunks could not be allocated yet. Fixes: 9cb8374 ("RDMA/rtrs: server: main functionality") Link: https://lore.kernel.org/r/20201023074353.21946-6-jinpu.wang@cloud.ionos.com Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com> Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

Mismatch in probe platform_set_drvdata set's and method's that call dev_get_platdata will result in "Unable to handle kernel NULL pointer dereference", let's use according method for getting driver data after platform_set_drvdata. 8<--- cut here --- Unable to handle kernel NULL pointer dereference at virtual address 00000000 pgd = (ptrval) [00000000] *pgd=00000000 Internal error: Oops: 5 [#1] ARM Modules linked in: CPU: 0 PID: 1 Comm: swapper Not tainted 5.9.10-00003-g723e101e0037-dirty #4 Hardware name: Technologic Systems TS-72xx SBC PC is at ep93xx_rtc_read_time+0xc/0x2c LR is at __rtc_read_time+0x4c/0x8c [...] [<c02b01c8>] (ep93xx_rtc_read_time) from [<c02ac38c>] (__rtc_read_time+0x4c/0x8c) [<c02ac38c>] (__rtc_read_time) from [<c02ac3f8>] (rtc_read_time+0x2c/0x4c) [<c02ac3f8>] (rtc_read_time) from [<c02acc54>] (__rtc_read_alarm+0x28/0x358) [<c02acc54>] (__rtc_read_alarm) from [<c02abd80>] (__rtc_register_device+0x124/0x2ec) [<c02abd80>] (__rtc_register_device) from [<c02b028c>] (ep93xx_rtc_probe+0xa4/0xac) [<c02b028c>] (ep93xx_rtc_probe) from [<c026424c>] (platform_drv_probe+0x24/0x5c) [<c026424c>] (platform_drv_probe) from [<c0262918>] (really_probe+0x218/0x374) [<c0262918>] (really_probe) from [<c0262da0>] (device_driver_attach+0x44/0x60) [<c0262da0>] (device_driver_attach) from [<c0262e70>] (__driver_attach+0xb4/0xc0) [<c0262e70>] (__driver_attach) from [<c0260d44>] (bus_for_each_dev+0x68/0xac) [<c0260d44>] (bus_for_each_dev) from [<c026223c>] (driver_attach+0x18/0x24) [<c026223c>] (driver_attach) from [<c0261dd8>] (bus_add_driver+0x150/0x1b4) [<c0261dd8>] (bus_add_driver) from [<c026342c>] (driver_register+0xb0/0xf4) [<c026342c>] (driver_register) from [<c0264210>] (__platform_driver_register+0x30/0x48) [<c0264210>] (__platform_driver_register) from [<c04cb9ac>] (ep93xx_rtc_driver_init+0x10/0x1c) [<c04cb9ac>] (ep93xx_rtc_driver_init) from [<c000973c>] (do_one_initcall+0x7c/0x1c0) [<c000973c>] (do_one_initcall) from [<c04b9ecc>] (kernel_init_freeable+0x168/0x1ac) [<c04b9ecc>] (kernel_init_freeable) from [<c03b2228>] (kernel_init+0x8/0xf4) [<c03b2228>] (kernel_init) from [<c00082c0>] (ret_from_fork+0x14/0x34) Exception stack(0xc441dfb0 to 0xc441dff8) dfa0: 00000000 00000000 00000000 00000000 dfc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 dfe0: 00000000 00000000 00000000 00000000 00000013 00000000 Code: e12fff1e e92d4010 e590303c e1a02001 (e5933000) ---[ end trace c914d6030eaa95c8 ]--- Fixes: b809d19 ("rtc: ep93xx: stop setting platform_data") Signed-off-by: Nikita Shubin <nikita.shubin@maquefel.me> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20201201095507.10317-1-nikita.shubin@maquefel.me

Like other tunneling interfaces, the bareudp doesn't need TXLOCK. So, It is good to set the NETIF_F_LLTX flag to improve performance and to avoid lockdep's false-positive warning. Test commands: ip netns add A ip netns add B ip link add veth0 netns A type veth peer name veth1 netns B ip netns exec A ip link set veth0 up ip netns exec A ip a a 10.0.0.1/24 dev veth0 ip netns exec B ip link set veth1 up ip netns exec B ip a a 10.0.0.2/24 dev veth1 for i in {2..1} do let A=$i-1 ip netns exec A ip link add bareudp$i type bareudp \ dstport $i ethertype ip ip netns exec A ip link set bareudp$i up ip netns exec A ip a a 10.0.$i.1/24 dev bareudp$i ip netns exec A ip r a 10.0.$i.2 encap ip src 10.0.$A.1 \ dst 10.0.$A.2 via 10.0.$i.2 dev bareudp$i ip netns exec B ip link add bareudp$i type bareudp \ dstport $i ethertype ip ip netns exec B ip link set bareudp$i up ip netns exec B ip a a 10.0.$i.2/24 dev bareudp$i ip netns exec B ip r a 10.0.$i.1 encap ip src 10.0.$A.2 \ dst 10.0.$A.1 via 10.0.$i.1 dev bareudp$i done ip netns exec A ping 10.0.2.2 Splat looks like: [ 96.992803][ T822] ============================================ [ 96.993954][ T822] WARNING: possible recursive locking detected [ 96.995102][ T822] 5.10.0+ #819 Not tainted [ 96.995927][ T822] -------------------------------------------- [ 96.997091][ T822] ping/822 is trying to acquire lock: [ 96.998083][ T822] ffff88810f753898 (_xmit_NONE#2){+.-.}-{2:2}, at: __dev_queue_xmit+0x1f52/0x2960 [ 96.999813][ T822] [ 96.999813][ T822] but task is already holding lock: [ 97.001192][ T822] ffff88810c385498 (_xmit_NONE#2){+.-.}-{2:2}, at: __dev_queue_xmit+0x1f52/0x2960 [ 97.002908][ T822] [ 97.002908][ T822] other info that might help us debug this: [ 97.004401][ T822] Possible unsafe locking scenario: [ 97.004401][ T822] [ 97.005784][ T822] CPU0 [ 97.006407][ T822] ---- [ 97.007010][ T822] lock(_xmit_NONE#2); [ 97.007779][ T822] lock(_xmit_NONE#2); [ 97.008550][ T822] [ 97.008550][ T822] *** DEADLOCK *** [ 97.008550][ T822] [ 97.010057][ T822] May be due to missing lock nesting notation [ 97.010057][ T822] [ 97.011594][ T822] 7 locks held by ping/822: [ 97.012426][ T822] #0: ffff888109a144f0 (sk_lock-AF_INET){+.+.}-{0:0}, at: raw_sendmsg+0x12f7/0x2b00 [ 97.014191][ T822] #1: ffffffffbce2f5a0 (rcu_read_lock_bh){....}-{1:2}, at: ip_finish_output2+0x249/0x2020 [ 97.016045][ T822] #2: ffffffffbce2f5a0 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x1fd/0x2960 [ 97.017897][ T822] #3: ffff88810c385498 (_xmit_NONE#2){+.-.}-{2:2}, at: __dev_queue_xmit+0x1f52/0x2960 [ 97.019684][ T822] #4: ffffffffbce2f600 (rcu_read_lock){....}-{1:2}, at: bareudp_xmit+0x31b/0x3690 [bareudp] [ 97.021573][ T822] #5: ffffffffbce2f5a0 (rcu_read_lock_bh){....}-{1:2}, at: ip_finish_output2+0x249/0x2020 [ 97.023424][ T822] #6: ffffffffbce2f5a0 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x1fd/0x2960 [ 97.025259][ T822] [ 97.025259][ T822] stack backtrace: [ 97.026349][ T822] CPU: 3 PID: 822 Comm: ping Not tainted 5.10.0+ #819 [ 97.027609][ T822] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 [ 97.029407][ T822] Call Trace: [ 97.030015][ T822] dump_stack+0x99/0xcb [ 97.030783][ T822] __lock_acquire.cold.77+0x149/0x3a9 [ 97.031773][ T822] ? stack_trace_save+0x81/0xa0 [ 97.032661][ T822] ? register_lock_class+0x1910/0x1910 [ 97.033673][ T822] ? register_lock_class+0x1910/0x1910 [ 97.034679][ T822] ? rcu_read_lock_sched_held+0x91/0xc0 [ 97.035697][ T822] ? rcu_read_lock_bh_held+0xa0/0xa0 [ 97.036690][ T822] lock_acquire+0x1b2/0x730 [ 97.037515][ T822] ? __dev_queue_xmit+0x1f52/0x2960 [ 97.038466][ T822] ? check_flags+0x50/0x50 [ 97.039277][ T822] ? netif_skb_features+0x296/0x9c0 [ 97.040226][ T822] ? validate_xmit_skb+0x29/0xb10 [ 97.041151][ T822] _raw_spin_lock+0x30/0x70 [ 97.041977][ T822] ? __dev_queue_xmit+0x1f52/0x2960 [ 97.042927][ T822] __dev_queue_xmit+0x1f52/0x2960 [ 97.043852][ T822] ? netdev_core_pick_tx+0x290/0x290 [ 97.044824][ T822] ? mark_held_locks+0xb7/0x120 [ 97.045712][ T822] ? lockdep_hardirqs_on_prepare+0x12c/0x3e0 [ 97.046824][ T822] ? __local_bh_enable_ip+0xa5/0xf0 [ 97.047771][ T822] ? ___neigh_create+0x12a8/0x1eb0 [ 97.048710][ T822] ? trace_hardirqs_on+0x41/0x120 [ 97.049626][ T822] ? ___neigh_create+0x12a8/0x1eb0 [ 97.050556][ T822] ? __local_bh_enable_ip+0xa5/0xf0 [ 97.051509][ T822] ? ___neigh_create+0x12a8/0x1eb0 [ 97.052443][ T822] ? check_chain_key+0x244/0x5f0 [ 97.053352][ T822] ? rcu_read_lock_bh_held+0x56/0xa0 [ 97.054317][ T822] ? ip_finish_output2+0x6ea/0x2020 [ 97.055263][ T822] ? pneigh_lookup+0x410/0x410 [ 97.056135][ T822] ip_finish_output2+0x6ea/0x2020 [ ... ] Acked-by: Guillaume Nault <gnault@redhat.com> Fixes: 571912c ("net: UDP tunnel encapsulation module for tunnelling different protocols like MPLS, IP, NSH etc.") Signed-off-by: Taehee Yoo <ap420073@gmail.com> Link: https://lore.kernel.org/r/20201228152136.24215-1-ap420073@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Latest bpf tree has a bug for bpf_iter selftest: $ ./test_progs -n 4/25 test_bpf_sk_storage_get:PASS:bpf_iter_bpf_sk_storage_helpers__open_and_load 0 nsec test_bpf_sk_storage_get:PASS:socket 0 nsec ... do_dummy_read:PASS:read 0 nsec test_bpf_sk_storage_get:FAIL:bpf_map_lookup_elem map value wasn't set correctly (expected 1792, got -1, err=0) #4/25 bpf_sk_storage_get:FAIL #4 bpf_iter:FAIL Summary: 0/0 PASSED, 0 SKIPPED, 2 FAILED When doing merge conflict resolution, Commit 4bfc471 missed to save curr_task to seq_file private data. The task pointer in seq_file private data is passed to bpf program. This caused NULL-pointer task passed to bpf program which will immediately return upon checking whether task pointer is NULL. This patch added back the assignment of curr_task to seq_file private data and fixed the issue. Fixes: 4bfc471 ("Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf") Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20201231052418.577024-1-yhs@fb.com

Ido Schimmel says: ==================== nexthop: Various fixes This series contains various fixes for the nexthop code. The bugs were uncovered during the development of resilient nexthop groups. Patches #1-#2 fix the error path of nexthop_create_group(). I was not able to trigger these bugs with current code, but it is possible with the upcoming resilient nexthop groups code which adds a user controllable memory allocation further in the function. Patch #3 fixes wrong validation of netlink attributes. Patch #4 fixes wrong invocation of mausezahn in a selftest. ==================== Link: https://lore.kernel.org/r/20210107144824.1135691-1-idosch@idosch.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>

We had kernel panic, it is caused by unload module and last close confirmation. call trace: [1196029.743127] free_sess+0x15/0x50 [rtrs_client] [1196029.743128] rtrs_clt_close+0x4c/0x70 [rtrs_client] [1196029.743129] ? rnbd_clt_unmap_device+0x1b0/0x1b0 [rnbd_client] [1196029.743130] close_rtrs+0x25/0x50 [rnbd_client] [1196029.743131] rnbd_client_exit+0x93/0xb99 [rnbd_client] [1196029.743132] __x64_sys_delete_module+0x190/0x260 And in the crashdump confirmation kworker is also running. PID: 6943 TASK: ffff9e2ac8098000 CPU: 4 COMMAND: "kworker/4:2" #0 [ffffb206cf337c30] __schedule at ffffffff9f93f891 #1 [ffffb206cf337cc8] schedule at ffffffff9f93fe98 #2 [ffffb206cf337cd0] schedule_timeout at ffffffff9f943938 #3 [ffffb206cf337d50] wait_for_completion at ffffffff9f9410a7 #4 [ffffb206cf337da0] __flush_work at ffffffff9f08ce0e #5 [ffffb206cf337e20] rtrs_clt_close_conns at ffffffffc0d5f668 [rtrs_client] #6 [ffffb206cf337e48] rtrs_clt_close at ffffffffc0d5f801 [rtrs_client] #7 [ffffb206cf337e68] close_rtrs at ffffffffc0d26255 [rnbd_client] #8 [ffffb206cf337e78] free_sess at ffffffffc0d262ad [rnbd_client] #9 [ffffb206cf337e88] rnbd_clt_put_dev at ffffffffc0d266a7 [rnbd_client] The problem is both code path try to close same session, which lead to panic. To fix it, just skip the sess if the refcount already drop to 0. Fixes: f7a7a5c ("block/rnbd: client: main functionality") Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com> Reviewed-by: Gioh Kim <gi-oh.kim@cloud.ionos.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>

nickdesaulniers added [BUG] Untriaged Something isn't working [BUG] llvm A bug that should be fixed in upstream LLVM labels Mar 22, 2018

nickdesaulniers added this to the ARCH=arm64 defconfig milestone Mar 22, 2018

nickdesaulniers added the [PATCH] Exists There is a patch that fixes this issue label Mar 27, 2018

nickdesaulniers closed this as completed May 14, 2018

nickdesaulniers removed the [BUG] Untriaged Something isn't working label May 14, 2018

cwhuang mentioned this issue Jun 26, 2018

clang crash compiling binder.o for 32b x86 #22

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nickdesaulniers added the [ARCH] arm64 This bug impacts ARCH=arm64 label Sep 13, 2018

nickdesaulniers assigned m-gupta Sep 13, 2018

nickdesaulniers mentioned this issue Oct 20, 2020

Assertion `BitWidth == RHS.BitWidth && "Comparison requires equal bit widths"' failed #1183

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jcai19 mentioned this issue Dec 2, 2020

invalid instruction in arch/arm/kernel/hyp-stub.S #1155

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clang ias: build failure for arch/arm/probes/kprobes/test-arm.c #1271

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thinlto: Crash during final link #1322

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prabhatKrMishra mentioned this issue Jun 4, 2021

invalid operand for umov #1392

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ms178 mentioned this issue Sep 20, 2021

Clang Full LTO broken on Linux 5.14.6 with LLVM/Clang 14-git 84b07c9b #1460

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Erro module 'fs/jbd2/commit.o' on function '@jbd2_submit_inode_data' #2008

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Issue with Qualcomm kernel modules and BTI since at least LLVM 17 #2022

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support for "r" prefixed variables in ARM inline assembly #4

support for "r" prefixed variables in ARM inline assembly #4

nickdesaulniers commented Mar 22, 2018 •

edited by nathanchance

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nickdesaulniers commented Mar 22, 2018

nickdesaulniers commented Mar 26, 2018

mkaehlcke commented Apr 3, 2018

support for "r" prefixed variables in ARM inline assembly #4

support for "r" prefixed variables in ARM inline assembly #4

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nickdesaulniers commented Mar 22, 2018 • edited by nathanchance Loading

nickdesaulniers commented Mar 22, 2018

nickdesaulniers commented Mar 26, 2018

mkaehlcke commented Apr 3, 2018

nickdesaulniers commented Mar 22, 2018 •

edited by nathanchance

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