RFE: audit device attach/detach events #1

pcmoore · 2016-02-26T22:12:58Z

Hook the audit system into the Linux Kernel's device layer to capture and record device attach and detach events, also hook significant upper layers to capture notable metadata about the device, e.g. serial #, device and vendor IDs, etc.

GH Feature Page

The-Mule · 2017-02-16T07:30:08Z

Thanks for "Functional Testing and Verification" section in Feature Page Paul. USB disks are good examples of removable devices to trigger new events. Are there any other examples? Does it even make sense to try something else than USB disks (from what I see, events are generated from a layer which is transparent to any removable device - iow testing usb disks should be sufficient IMHO)?

pcmoore · 2017-02-17T21:28:00Z

Thanks for "Functional Testing and Verification" section in Feature Page Paul. USB disks are good examples of removable devices to trigger new events. Are there any other examples?

USB devices in general are probably the easiest to test due the hotplug nature of the bus. Besides USB storage devices, I think USB HID devices (e.g. keyboard, mouse, etc.) would be easy to test and a common case. UVC devices (e.g. webcams) would be another easy thing to test.

Does it even make sense to try something else than USB disks (from what I see, events are generated from a layer which is transparent to any removable device - iow testing usb disks should be sufficient IMHO)?

USB is likely to be the most important, but you are correct, this should catch any device, regardless of the underlying bus.

pcmoore · 2017-02-17T21:29:27Z

@wmealing it has been a while since we spoke about this, but if I remember correctly you were planning on continuing work on this, any progress you can report?

rcu_dereference_key() and user_key_payload() are currently being used in two different, incompatible ways: (1) As a wrapper to rcu_dereference() - when only the RCU read lock used to protect the key. (2) As a wrapper to rcu_dereference_protected() - when the key semaphor is used to protect the key and the may be being modified. Fix this by splitting both of the key wrappers to produce: (1) RCU accessors for keys when caller has the key semaphore locked: dereference_key_locked() user_key_payload_locked() (2) RCU accessors for keys when caller holds the RCU read lock: dereference_key_rcu() user_key_payload_rcu() This should fix following warning in the NFS idmapper =============================== [ INFO: suspicious RCU usage. ] 4.10.0 #1 Tainted: G W ------------------------------- ./include/keys/user-type.h:53 suspicious rcu_dereference_protected() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 0 1 lock held by mount.nfs/5987: #0: (rcu_read_lock){......}, at: [<d000000002527abc>] nfs_idmap_get_key+0x15c/0x420 [nfsv4] stack backtrace: CPU: 1 PID: 5987 Comm: mount.nfs Tainted: G W 4.10.0 #1 Call Trace: dump_stack+0xe8/0x154 (unreliable) lockdep_rcu_suspicious+0x140/0x190 nfs_idmap_get_key+0x380/0x420 [nfsv4] nfs_map_name_to_uid+0x2a0/0x3b0 [nfsv4] decode_getfattr_attrs+0xfac/0x16b0 [nfsv4] decode_getfattr_generic.constprop.106+0xbc/0x150 [nfsv4] nfs4_xdr_dec_lookup_root+0xac/0xb0 [nfsv4] rpcauth_unwrap_resp+0xe8/0x140 [sunrpc] call_decode+0x29c/0x910 [sunrpc] __rpc_execute+0x140/0x8f0 [sunrpc] rpc_run_task+0x170/0x200 [sunrpc] nfs4_call_sync_sequence+0x68/0xa0 [nfsv4] _nfs4_lookup_root.isra.44+0xd0/0xf0 [nfsv4] nfs4_lookup_root+0xe0/0x350 [nfsv4] nfs4_lookup_root_sec+0x70/0xa0 [nfsv4] nfs4_find_root_sec+0xc4/0x100 [nfsv4] nfs4_proc_get_rootfh+0x5c/0xf0 [nfsv4] nfs4_get_rootfh+0x6c/0x190 [nfsv4] nfs4_server_common_setup+0xc4/0x260 [nfsv4] nfs4_create_server+0x278/0x3c0 [nfsv4] nfs4_remote_mount+0x50/0xb0 [nfsv4] mount_fs+0x74/0x210 vfs_kern_mount+0x78/0x220 nfs_do_root_mount+0xb0/0x140 [nfsv4] nfs4_try_mount+0x60/0x100 [nfsv4] nfs_fs_mount+0x5ec/0xda0 [nfs] mount_fs+0x74/0x210 vfs_kern_mount+0x78/0x220 do_mount+0x254/0xf70 SyS_mount+0x94/0x100 system_call+0x38/0xe0 Reported-by: Jan Stancek <jstancek@redhat.com> Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Jan Stancek <jstancek@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com>

The code where sk_clone() came from created a new socket and locked it, but then, on the error path didn't unlock it. This problem stayed there for a long while, till b0691c8 ("net: Unlock sock before calling sk_free()") fixed it, but unfortunately the callers of sk_clone() (now sk_clone_locked()) were not audited and the one in dccp_create_openreq_child() remained. Now in the age of the syskaller fuzzer, this was finally uncovered, as reported by Dmitry: ---- 8< ---- I've got the following report while running syzkaller fuzzer on 86292b3 ("Merge branch 'akpm' (patches from Andrew)") [ BUG: held lock freed! ] 4.10.0+ #234 Not tainted ------------------------- syz-executor6/6898 is freeing memory ffff88006286cac0-ffff88006286d3b7, with a lock still held there! (slock-AF_INET6){+.-...}, at: [<ffffffff8362c2c9>] spin_lock include/linux/spinlock.h:299 [inline] (slock-AF_INET6){+.-...}, at: [<ffffffff8362c2c9>] sk_clone_lock+0x3d9/0x12c0 net/core/sock.c:1504 5 locks held by syz-executor6/6898: #0: (sk_lock-AF_INET6){+.+.+.}, at: [<ffffffff839a34b4>] lock_sock include/net/sock.h:1460 [inline] #0: (sk_lock-AF_INET6){+.+.+.}, at: [<ffffffff839a34b4>] inet_stream_connect+0x44/0xa0 net/ipv4/af_inet.c:681 #1: (rcu_read_lock){......}, at: [<ffffffff83bc1c2a>] inet6_csk_xmit+0x12a/0x5d0 net/ipv6/inet6_connection_sock.c:126 #2: (rcu_read_lock){......}, at: [<ffffffff8369b424>] __skb_unlink include/linux/skbuff.h:1767 [inline] #2: (rcu_read_lock){......}, at: [<ffffffff8369b424>] __skb_dequeue include/linux/skbuff.h:1783 [inline] #2: (rcu_read_lock){......}, at: [<ffffffff8369b424>] process_backlog+0x264/0x730 net/core/dev.c:4835 #3: (rcu_read_lock){......}, at: [<ffffffff83aeb5c0>] ip6_input_finish+0x0/0x1700 net/ipv6/ip6_input.c:59 #4: (slock-AF_INET6){+.-...}, at: [<ffffffff8362c2c9>] spin_lock include/linux/spinlock.h:299 [inline] #4: (slock-AF_INET6){+.-...}, at: [<ffffffff8362c2c9>] sk_clone_lock+0x3d9/0x12c0 net/core/sock.c:1504 Fix it just like was done by b0691c8 ("net: Unlock sock before calling sk_free()"). Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: Cong Wang <xiyou.wangcong@gmail.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Gerrit Renker <gerrit@erg.abdn.ac.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20170301153510.GE15145@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>

The locking in lirc needs improvement, but for now just fix this potential deadlock. ====================================================== [ INFO: possible circular locking dependency detected ] 4.10.0-rc1+ #1 Not tainted ------------------------------------------------------- bash/2502 is trying to acquire lock: (ir_raw_handler_lock){+.+.+.}, at: [<ffffffffc06f6a5e>] ir_raw_encode_scancode+0x3e/0xb0 [rc_core] but task is already holding lock: (&dev->lock){+.+.+.}, at: [<ffffffffc06f511f>] store_filter+0x9f/0x240 [rc_core] which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&dev->lock){+.+.+.}: [<ffffffffa110adad>] lock_acquire+0xfd/0x200 [<ffffffffa1921327>] mutex_lock_nested+0x77/0x6d0 [<ffffffffc06f436a>] rc_open+0x2a/0x80 [rc_core] [<ffffffffc07114ca>] lirc_dev_fop_open+0xda/0x1e0 [lirc_dev] [<ffffffffa12975e0>] chrdev_open+0xb0/0x210 [<ffffffffa128eb5a>] do_dentry_open+0x20a/0x2f0 [<ffffffffa128ffcc>] vfs_open+0x4c/0x80 [<ffffffffa12a35ec>] path_openat+0x5bc/0xc00 [<ffffffffa12a5271>] do_filp_open+0x91/0x100 [<ffffffffa12903f0>] do_sys_open+0x130/0x220 [<ffffffffa12904fe>] SyS_open+0x1e/0x20 [<ffffffffa19278c1>] entry_SYSCALL_64_fastpath+0x1f/0xc2 -> #1 (lirc_dev_lock){+.+.+.}: [<ffffffffa110adad>] lock_acquire+0xfd/0x200 [<ffffffffa1921327>] mutex_lock_nested+0x77/0x6d0 [<ffffffffc0711f47>] lirc_register_driver+0x67/0x59b [lirc_dev] [<ffffffffc06db7f4>] ir_lirc_register+0x1f4/0x260 [ir_lirc_codec] [<ffffffffc06f6cac>] ir_raw_handler_register+0x7c/0xb0 [rc_core] [<ffffffffc0398010>] 0xffffffffc0398010 [<ffffffffa1002192>] do_one_initcall+0x52/0x1b0 [<ffffffffa11ef5c8>] do_init_module+0x5f/0x1fa [<ffffffffa11566b5>] load_module+0x2675/0x2b00 [<ffffffffa1156dcf>] SYSC_finit_module+0xdf/0x110 [<ffffffffa1156e1e>] SyS_finit_module+0xe/0x10 [<ffffffffa1003f5c>] do_syscall_64+0x6c/0x1f0 [<ffffffffa1927989>] return_from_SYSCALL_64+0x0/0x7a -> #0 (ir_raw_handler_lock){+.+.+.}: [<ffffffffa110a7b7>] __lock_acquire+0x10f7/0x1290 [<ffffffffa110adad>] lock_acquire+0xfd/0x200 [<ffffffffa1921327>] mutex_lock_nested+0x77/0x6d0 [<ffffffffc06f6a5e>] ir_raw_encode_scancode+0x3e/0xb0 [rc_core] [<ffffffffc0b0f492>] loop_set_wakeup_filter+0x62/0xbd [rc_loopback] [<ffffffffc06f522a>] store_filter+0x1aa/0x240 [rc_core] [<ffffffffa15e46f8>] dev_attr_store+0x18/0x30 [<ffffffffa13318e5>] sysfs_kf_write+0x45/0x60 [<ffffffffa1330b55>] kernfs_fop_write+0x155/0x1e0 [<ffffffffa1290797>] __vfs_write+0x37/0x160 [<ffffffffa12921f8>] vfs_write+0xc8/0x1e0 [<ffffffffa12936e8>] SyS_write+0x58/0xc0 [<ffffffffa19278c1>] entry_SYSCALL_64_fastpath+0x1f/0xc2 other info that might help us debug this: Chain exists of: ir_raw_handler_lock --> lirc_dev_lock --> &dev->lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&dev->lock); lock(lirc_dev_lock); lock(&dev->lock); lock(ir_raw_handler_lock); *** DEADLOCK *** 4 locks held by bash/2502: #0: (sb_writers#4){.+.+.+}, at: [<ffffffffa12922c5>] vfs_write+0x195/0x1e0 #1: (&of->mutex){+.+.+.}, at: [<ffffffffa1330b1f>] kernfs_fop_write+0x11f/0x1e0 #2: (s_active#215){.+.+.+}, at: [<ffffffffa1330b28>] kernfs_fop_write+0x128/0x1e0 #3: (&dev->lock){+.+.+.}, at: [<ffffffffc06f511f>] store_filter+0x9f/0x240 [rc_core] stack backtrace: CPU: 3 PID: 2502 Comm: bash Not tainted 4.10.0-rc1+ #1 Hardware name: /DG45ID, BIOS IDG4510H.86A.0135.2011.0225.1100 02/25/2011 Call Trace: dump_stack+0x86/0xc3 print_circular_bug+0x1be/0x210 __lock_acquire+0x10f7/0x1290 lock_acquire+0xfd/0x200 ? ir_raw_encode_scancode+0x3e/0xb0 [rc_core] ? ir_raw_encode_scancode+0x3e/0xb0 [rc_core] mutex_lock_nested+0x77/0x6d0 ? ir_raw_encode_scancode+0x3e/0xb0 [rc_core] ? loop_set_wakeup_filter+0x44/0xbd [rc_loopback] ir_raw_encode_scancode+0x3e/0xb0 [rc_core] loop_set_wakeup_filter+0x62/0xbd [rc_loopback] ? loop_set_tx_duty_cycle+0x70/0x70 [rc_loopback] store_filter+0x1aa/0x240 [rc_core] dev_attr_store+0x18/0x30 sysfs_kf_write+0x45/0x60 kernfs_fop_write+0x155/0x1e0 __vfs_write+0x37/0x160 ? rcu_read_lock_sched_held+0x4a/0x80 ? rcu_sync_lockdep_assert+0x2f/0x60 ? __sb_start_write+0x10c/0x220 ? vfs_write+0x195/0x1e0 ? security_file_permission+0x3b/0xc0 vfs_write+0xc8/0x1e0 SyS_write+0x58/0xc0 entry_SYSCALL_64_fastpath+0x1f/0xc2 Signed-off-by: Sean Young <sean@mess.org> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

nvt_write_wakeup_codes acquires the same lock as the ISR but doesn't disable interrupts on the local CPU. This caused the following deadlock. Fix this by using spin_lock_irqsave. [ 432.362008] ================================ [ 432.362074] WARNING: inconsistent lock state [ 432.362144] 4.10.0-rc7-next-20170210 #1 Not tainted [ 432.362219] -------------------------------- [ 432.362286] inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage. [ 432.362379] swapper/0/0 [HC1[1]:SC0[0]:HE0:SE1] takes: [ 432.362457] (&(&nvt->lock)->rlock){?.+...}, at: [<ffffffffa016b17d>] nvt_cir_isr+0x2d/0x520 [nuvoton_cir] [ 432.362611] {HARDIRQ-ON-W} state was registered at: [ 432.362686] [ 432.362698] [<ffffffff810adb7c>] __lock_acquire+0x5dc/0x1260 [ 432.362812] [ 432.362817] [<ffffffff810aec29>] lock_acquire+0xe9/0x1d0 [ 432.362927] [ 432.362934] [<ffffffff81609f63>] _raw_spin_lock+0x33/0x50 [ 432.363045] [ 432.363051] [<ffffffffa016b822>] nvt_write_wakeup_codes.isra.12+0x22/0xe0 [nuvoton_cir] [ 432.363193] [ 432.363199] [<ffffffffa016b9bf>] wakeup_data_store+0xdf/0xf0 [nuvoton_cir] [ 432.363327] [ 432.363333] [<ffffffff81484223>] dev_attr_store+0x13/0x20 [ 432.363441] [ 432.363449] [<ffffffff81232450>] sysfs_kf_write+0x40/0x50 [ 432.363558] [ 432.363564] [<ffffffff81231640>] kernfs_fop_write+0x150/0x1e0 [ 432.363676] [ 432.363685] [<ffffffff811b36a3>] __vfs_write+0x23/0x120 [ 432.363791] [ 432.363798] [<ffffffff811b4d53>] vfs_write+0xc3/0x1e0 [ 432.363902] [ 432.363909] [<ffffffff811b6124>] SyS_write+0x44/0xa0 [ 432.364012] [ 432.364021] [<ffffffff81002c47>] do_syscall_64+0x57/0x140 [ 432.364129] [ 432.364135] [<ffffffff8160a9e4>] return_from_SYSCALL_64+0x0/0x7a [ 432.364252] irq event stamp: 415118 [ 432.364313] hardirqs last enabled at (415115): [<ffffffff814fd2eb>] cpuidle_enter_state+0x11b/0x370 [ 432.364445] hardirqs last disabled at (415116): [<ffffffff8160b2cb>] common_interrupt+0x8b/0x90 [ 432.364573] softirqs last enabled at (415118): [<ffffffff8106157c>] _local_bh_enable+0x1c/0x50 [ 432.364699] softirqs last disabled at (415117): [<ffffffff810629a3>] irq_enter+0x43/0x60 [ 432.364814] other info that might help us debug this: [ 432.364909] Possible unsafe locking scenario: [ 432.367821] CPU0 [ 432.370645] ---- [ 432.373432] lock(&(&nvt->lock)->rlock); [ 432.376228] <Interrupt> [ 432.378982] lock(&(&nvt->lock)->rlock); [ 432.381757] *** DEADLOCK *** [ 432.389888] no locks held by swapper/0/0. [ 432.392574] stack backtrace: [ 432.397774] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.10.0-rc7-next-20170210 #1 [ 432.400375] Hardware name: ZOTAC ZBOX-CI321NANO/ZBOX-CI321NANO, BIOS B246P105 06/01/2015 [ 432.403023] Call Trace: [ 432.405636] <IRQ> [ 432.408208] dump_stack+0x68/0x93 [ 432.410775] print_usage_bug+0x1dd/0x1f0 [ 432.413334] mark_lock+0x559/0x5c0 [ 432.415871] ? print_shortest_lock_dependencies+0x1a0/0x1a0 [ 432.418431] __lock_acquire+0x6b1/0x1260 [ 432.420941] lock_acquire+0xe9/0x1d0 [ 432.423396] ? nvt_cir_isr+0x2d/0x520 [nuvoton_cir] [ 432.425844] _raw_spin_lock+0x33/0x50 [ 432.428252] ? nvt_cir_isr+0x2d/0x520 [nuvoton_cir] [ 432.430670] nvt_cir_isr+0x2d/0x520 [nuvoton_cir] [ 432.433085] __handle_irq_event_percpu+0x43/0x330 [ 432.435493] handle_irq_event_percpu+0x1e/0x50 [ 432.437884] handle_irq_event+0x34/0x60 [ 432.440236] handle_edge_irq+0x6a/0x150 [ 432.442561] handle_irq+0x15/0x20 [ 432.444854] do_IRQ+0x57/0x110 [ 432.447115] common_interrupt+0x90/0x90 [ 432.449380] RIP: 0010:cpuidle_enter_state+0x120/0x370 [ 432.451653] RSP: 0018:ffffffff81c03dd8 EFLAGS: 00000206 ORIG_RAX: ffffffffffffffcc [ 432.453994] RAX: ffffffff81c14500 RBX: 0000000000000008 RCX: 00000064aac6f2d2 [ 432.456349] RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffffff81c14500 [ 432.458704] RBP: ffffffff81c03e18 R08: cccccccccccccccd R09: 0000000000000018 [ 432.461072] R10: 0000000000000000 R11: 0000000000000000 R12: ffff880100a21260 [ 432.463450] R13: ffffffff81c7e6f8 R14: 0000000000000008 R15: ffffffff81c7e6e0 [ 432.465819] </IRQ> [ 432.468104] ? cpuidle_enter_state+0x11b/0x370 [ 432.470413] cpuidle_enter+0x12/0x20 [ 432.472698] call_cpuidle+0x1e/0x40 [ 432.474967] do_idle+0xe3/0x1c0 [ 432.477172] cpu_startup_entry+0x18/0x20 [ 432.479376] rest_init+0x130/0x140 [ 432.481565] start_kernel+0x3cc/0x3d9 [ 432.483750] x86_64_start_reservations+0x2a/0x2c [ 432.485980] x86_64_start_kernel+0x178/0x18b [ 432.488222] start_cpu+0x14/0x14 [ 432.490453] ? start_cpu+0x14/0x14 Fixes: 97c1297 "[media] rc: nuvoton-cir: Add support wakeup via sysfs filter callback" Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Sean Young <sean@mess.org> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

This leads to a BUG of the following form: [ 174.512861] switch: port 2(vif3.0) entered disabled state [ 174.522735] BUG: sleeping function called from invalid context at /home/build/linux-linus/mm/vmalloc.c:1441 [ 174.523451] in_atomic(): 1, irqs_disabled(): 0, pid: 28, name: xenwatch [ 174.524131] CPU: 1 PID: 28 Comm: xenwatch Tainted: G W 4.10.0upstream-11073-g4977ab6-dirty #1 [ 174.524819] Hardware name: MSI MS-7680/H61M-P23 (MS-7680), BIOS V17.0 03/14/2011 [ 174.525517] Call Trace: [ 174.526217] show_stack+0x23/0x60 [ 174.526899] dump_stack+0x5b/0x88 [ 174.527562] ___might_sleep+0xde/0x130 [ 174.528208] __might_sleep+0x35/0xa0 [ 174.528840] ? _raw_spin_unlock_irqrestore+0x13/0x20 [ 174.529463] ? __wake_up+0x40/0x50 [ 174.530089] remove_vm_area+0x20/0x90 [ 174.530724] __vunmap+0x1d/0xc0 [ 174.531346] ? delete_object_full+0x13/0x20 [ 174.531973] vfree+0x40/0x80 [ 174.532594] set_backend_state+0x18a/0xa90 [ 174.533221] ? dwc_scan_descriptors+0x24d/0x430 [ 174.533850] ? kfree+0x5b/0xc0 [ 174.534476] ? xenbus_read+0x3d/0x50 [ 174.535101] ? xenbus_read+0x3d/0x50 [ 174.535718] ? xenbus_gather+0x31/0x90 [ 174.536332] ? ___might_sleep+0xf6/0x130 [ 174.536945] frontend_changed+0x6b/0xd0 [ 174.537565] xenbus_otherend_changed+0x7d/0x80 [ 174.538185] frontend_changed+0x12/0x20 [ 174.538803] xenwatch_thread+0x74/0x110 [ 174.539417] ? woken_wake_function+0x20/0x20 [ 174.540049] kthread+0xe5/0x120 [ 174.540663] ? xenbus_printf+0x50/0x50 [ 174.541278] ? __kthread_init_worker+0x40/0x40 [ 174.541898] ret_from_fork+0x21/0x2c [ 174.548635] switch: port 2(vif3.0) entered disabled state This patch defers the vfree() until after the spinlock is released. Reported-by: Juergen Gross <jgross@suse.com> Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>

Paul Durrant says: ==================== xen-netback: update memory leak fix to avoid BUG Commit 9a6cdf5 "xen-netback: fix memory leaks on XenBus disconnect" added missing code to fix a memory leak by calling vfree() in the appropriate place. Unfortunately subsequent commit f16f1df "xen-netback: protect resource cleaning on XenBus disconnect" then wrapped this call to vfree() in a spin lock, leading to a BUG due to incorrect context. Patch #1 makes the existing code more readable Patch #2 fixes the problem ==================== Signed-off-by: David S. Miller <davem@davemloft.net>

pids_can_fork() is special in that the css association is guaranteed to be stable throughout the function and thus doesn't need RCU protection around task_css access. When determining the css to charge the pid, task_css_check() is used to override the RCU sanity check. While adding a warning message on fork rejection from pids limit, 135b8b3 ("cgroup: Add pids controller event when fork fails because of pid limit") incorrectly added a task_css access which is neither RCU protected or explicitly annotated. This triggers the following suspicious RCU usage warning when RCU debugging is enabled. cgroup: fork rejected by pids controller in =============================== [ ERR: suspicious RCU usage. ] 4.10.0-work+ #1 Not tainted ------------------------------- ./include/linux/cgroup.h:435 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 0 1 lock held by bash/1748: #0: (&cgroup_threadgroup_rwsem){+++++.}, at: [<ffffffff81052c96>] _do_fork+0xe6/0x6e0 stack backtrace: CPU: 3 PID: 1748 Comm: bash Not tainted 4.10.0-work+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.3-1.fc25 04/01/2014 Call Trace: dump_stack+0x68/0x93 lockdep_rcu_suspicious+0xd7/0x110 pids_can_fork+0x1c7/0x1d0 cgroup_can_fork+0x67/0xc0 copy_process.part.58+0x1709/0x1e90 _do_fork+0xe6/0x6e0 SyS_clone+0x19/0x20 do_syscall_64+0x5c/0x140 entry_SYSCALL64_slow_path+0x25/0x25 RIP: 0033:0x7f7853fab93a RSP: 002b:00007ffc12d05c90 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f7853fab93a RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007ffc12d05cc0 R08: 0000000000000000 R09: 00007f78548db700 R10: 00007f78548db9d0 R11: 0000000000000246 R12: 00000000000006d4 R13: 0000000000000001 R14: 0000000000000000 R15: 000055e3ebe2c04d /asdf There's no reason to dereference task_css again here when the associated css is already available. Fix it by replacing the task_cgroup() call with css->cgroup. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Mike Galbraith <efault@gmx.de> Fixes: 135b8b3 ("cgroup: Add pids controller event when fork fails because of pid limit") Cc: Kenny Yu <kennyyu@fb.com> Cc: stable@vger.kernel.org # v4.8+ Signed-off-by: Tejun Heo <tj@kernel.org>

Andrey reported the following kernel crash: kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 0 PID: 14446 Comm: syz-executor6 Not tainted 4.10.0+ #82 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 task: ffff88001f311700 task.stack: ffff88001f6e8000 RIP: 0010:ip6mr_sk_done+0x15a/0x3d0 net/ipv6/ip6mr.c:1618 RSP: 0018:ffff88001f6ef418 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 1ffff10003edde8c RCX: ffffc900043ee000 RDX: 0000000000000004 RSI: ffffffff83e3b3f8 RDI: 0000000000000020 RBP: ffff88001f6ef508 R08: fffffbfff0dcc5d8 R09: 0000000000000000 R10: ffffffff86e62ec0 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffff88001f6ef4e0 R15: ffff8800380a0040 FS: 00007f7a52cec700(0000) GS:ffff88003ec00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000061c500 CR3: 000000001f1ae000 CR4: 00000000000006f0 DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: rawv6_close+0x4c/0x80 net/ipv6/raw.c:1217 inet_release+0xed/0x1c0 net/ipv4/af_inet.c:425 inet6_release+0x50/0x70 net/ipv6/af_inet6.c:432 sock_release+0x8d/0x1e0 net/socket.c:597 __sock_create+0x39d/0x880 net/socket.c:1226 sock_create_kern+0x3f/0x50 net/socket.c:1243 inet_ctl_sock_create+0xbb/0x280 net/ipv4/af_inet.c:1526 icmpv6_sk_init+0x163/0x500 net/ipv6/icmp.c:954 ops_init+0x10a/0x550 net/core/net_namespace.c:115 setup_net+0x261/0x660 net/core/net_namespace.c:291 copy_net_ns+0x27e/0x540 net/core/net_namespace.c:396 9pnet_virtio: no channels available for device ./file1 create_new_namespaces+0x437/0x9b0 kernel/nsproxy.c:106 unshare_nsproxy_namespaces+0xae/0x1e0 kernel/nsproxy.c:205 SYSC_unshare kernel/fork.c:2281 [inline] SyS_unshare+0x64e/0x1000 kernel/fork.c:2231 entry_SYSCALL_64_fastpath+0x1f/0xc2 This is because net->ipv6.mr6_tables is not initialized at that point, ip6mr_rules_init() is not called yet, therefore on the error path when we iterator the list, we trigger this oops. Fix this by reordering ip6mr_rules_init() before icmpv6_sk_init(). Reported-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>

Julian Margetson reported a panic on his SAM460EX with Kernel 4.11-rc1: | Unable to handle kernel paging request for data at address 0x00000014 | Oops: Kernel access of bad area, sig: 11 [#1] | PREEMPT | Canyonlands | Modules linked in: | CPU: 0 PID: 1 Comm: swapper Not tainted [...] | task: ea838000 task.stack: ea836000 | NIP: c0599f5c LR: c0599dd8 CTR: 00000000 | REGS: ea837c80 TRAP: 0300 Not tainted [...] | MSR: 00029000 <CE,EE,ME> | CR: 24371242 XER: 20000000 | DEAR: 00000014 ESR: 00000000 | GPR00: c0599ce8 ea837d30 ea838000 c0e52dcc c0d56ffb [...] | NIP [c0599f5c] emac_probe+0xfb4/0x1304 | LR [c0599dd8] emac_probe+0xe30/0x1304 | Call Trace: | [ea837d30] [c0599ce8] emac_probe+0xd40/0x1304 (unreliable) | [ea837d80] [c0533504] platform_drv_probe+0x48/0x90 | [ea837da0] [c0531c14] driver_probe_device+0x15c/0x2c4 | [ea837dd0] [c0531e04] __driver_attach+0x88/0xb0 | ---[ end trace ... ]--- The problem is caused by emac_dt_phy_probe() returing success (0) for existing device-trees configurations that do not specify a "phy-handle" property. This caused the code to skip the existing phy probe and setup. Which led to essential phy related data-structures being uninitialized. This patch also removes the unused variable in emac_dt_phy_connect(). Fixes: a577ca6 ("net: emac: add support for device-tree based PHY discovery and setup") Reported-by: Julian Margetson <runaway@candw.ms> Signed-off-by: Christian Lamparter <chunkeey@googlemail.com> Signed-off-by: David S. Miller <davem@davemloft.net>

Patch series "userfaultfd non-cooperative further update for 4.11 merge window". Unfortunately I noticed one relevant bug in userfaultfd_exit while doing more testing. I've been doing testing before and this was also tested by kbuild bot and exercised by the selftest, but this bug never reproduced before. I dropped userfaultfd_exit as result. I dropped it because of implementation difficulty in receiving signals in __mmput and because I think -ENOSPC as result from the background UFFDIO_COPY should be enough already. Before I decided to remove userfaultfd_exit, I noticed userfaultfd_exit wasn't exercised by the selftest and when I tried to exercise it, after moving it to a more correct place in __mmput where it would make more sense and where the vma list is stable, it resulted in the event_wait_completion in D state. So then I added the second patch to be sure even if we call userfaultfd_event_wait_completion too late during task exit(), we won't risk to generate tasks in D state. The same check exists in handle_userfault() for the same reason, except it makes a difference there, while here is just a robustness check and it's run under WARN_ON_ONCE. While looking at the userfaultfd_event_wait_completion() function I looked back at its callers too while at it and I think it's not ok to stop executing dup_fctx on the fcs list because we relay on userfaultfd_event_wait_completion to execute userfaultfd_ctx_put(fctx->orig) which is paired against userfaultfd_ctx_get(fctx->orig) in dup_userfault just before list_add(fcs). This change only takes care of fctx->orig but this area also needs further review looking for similar problems in fctx->new. The only patch that is urgent is the first because it's an use after free during a SMP race condition that affects all processes if CONFIG_USERFAULTFD=y. Very hard to reproduce though and probably impossible without SLUB poisoning enabled. This patch (of 3): I once reproduced this oops with the userfaultfd selftest, it's not easily reproducible and it requires SLUB poisoning to reproduce. general protection fault: 0000 [#1] SMP Modules linked in: CPU: 2 PID: 18421 Comm: userfaultfd Tainted: G ------------ T 3.10.0+ #15 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.1-0-g8891697-prebuilt.qemu-project.org 04/01/2014 task: ffff8801f83b9440 ti: ffff8801f833c000 task.ti: ffff8801f833c000 RIP: 0010:[<ffffffff81451299>] [<ffffffff81451299>] userfaultfd_exit+0x29/0xa0 RSP: 0018:ffff8801f833fe80 EFLAGS: 00010202 RAX: ffff8801f833ffd8 RBX: 6b6b6b6b6b6b6b6b RCX: ffff8801f83b9440 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8800baf18600 RBP: ffff8801f833fee8 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000000 R11: ffffffff8127ceb3 R12: 0000000000000000 R13: ffff8800baf186b0 R14: ffff8801f83b99f8 R15: 00007faed746c700 FS: 0000000000000000(0000) GS:ffff88023fc80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 00007faf0966f028 CR3: 0000000001bc6000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: do_exit+0x297/0xd10 SyS_exit+0x17/0x20 tracesys+0xdd/0xe2 Code: 00 00 66 66 66 66 90 55 48 89 e5 41 54 53 48 83 ec 58 48 8b 1f 48 85 db 75 11 eb 73 66 0f 1f 44 00 00 48 8b 5b 10 48 85 db 74 64 <4c> 8b a3 b8 00 00 00 4d 85 e4 74 eb 41 f6 84 24 2c 01 00 00 80 RIP [<ffffffff81451299>] userfaultfd_exit+0x29/0xa0 RSP <ffff8801f833fe80> ---[ end trace 9fecd6dcb442846a ]--- In the debugger I located the "mm" pointer in the stack and walking mm->mmap->vm_next through the end shows the vma->vm_next list is fully consistent and it is null terminated list as expected. So this has to be an SMP race condition where userfaultfd_exit was running while the vma list was being modified by another CPU. When userfaultfd_exit() run one of the ->vm_next pointers pointed to SLAB_POISON (RBX is the vma pointer and is 0x6b6b..). The reason is that it's not running in __mmput but while there are still other threads running and it's not holding the mmap_sem (it can't as it has to wait the even to be received by the manager). So this is an use after free that was happening for all processes. One more implementation problem aside from the race condition: userfaultfd_exit has really to check a flag in mm->flags before walking the vma or it's going to slowdown the exit() path for regular tasks. One more implementation problem: at that point signals can't be delivered so it would also create a task in D state if the manager doesn't read the event. The major design issue: it overall looks superfluous as the manager can check for -ENOSPC in the background transfer: if (mmget_not_zero(ctx->mm)) { [..] } else { return -ENOSPC; } It's safer to roll it back and re-introduce it later if at all. [rppt@linux.vnet.ibm.com: documentation fixup after removal of UFFD_EVENT_EXIT] Link: http://lkml.kernel.org/r/1488345437-4364-1-git-send-email-rppt@linux.vnet.ibm.com Link: http://lkml.kernel.org/r/20170224181957.19736-2-aarcange@redhat.com Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Acked-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The system may panic when initialisation is done when almost all the memory is assigned to the huge pages using the kernel command line parameter hugepage=xxxx. Panic may occur like this: Unable to handle kernel paging request for data at address 0x00000000 Faulting instruction address: 0xc000000000302b88 Oops: Kernel access of bad area, sig: 11 [#1] SMP NR_CPUS=2048 [ 0.082424] NUMA pSeries Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.9.0-15-generic #16-Ubuntu task: c00000021ed01600 task.stack: c00000010d108000 NIP: c000000000302b88 LR: c000000000270e04 CTR: c00000000016cfd0 REGS: c00000010d10b2c0 TRAP: 0300 Not tainted (4.9.0-15-generic) MSR: 8000000002009033 <SF,VEC,EE,ME,IR,DR,RI,LE>[ 0.082770] CR: 28424422 XER: 00000000 CFAR: c0000000003d28b8 DAR: 0000000000000000 DSISR: 40000000 SOFTE: 1 GPR00: c000000000270e04 c00000010d10b540 c00000000141a300 c00000010fff6300 GPR04: 0000000000000000 00000000026012c0 c00000010d10b630 0000000487ab0000 GPR08: 000000010ee90000 c000000001454fd8 0000000000000000 0000000000000000 GPR12: 0000000000004400 c00000000fb80000 00000000026012c0 00000000026012c0 GPR16: 00000000026012c0 0000000000000000 0000000000000000 0000000000000002 GPR20: 000000000000000c 0000000000000000 0000000000000000 00000000024200c0 GPR24: c0000000016eef48 0000000000000000 c00000010fff7d00 00000000026012c0 GPR28: 0000000000000000 c00000010fff7d00 c00000010fff6300 c00000010d10b6d0 NIP mem_cgroup_soft_limit_reclaim+0xf8/0x4f0 LR do_try_to_free_pages+0x1b4/0x450 Call Trace: do_try_to_free_pages+0x1b4/0x450 try_to_free_pages+0xf8/0x270 __alloc_pages_nodemask+0x7a8/0xff0 new_slab+0x104/0x8e0 ___slab_alloc+0x620/0x700 __slab_alloc+0x34/0x60 kmem_cache_alloc_node_trace+0xdc/0x310 mem_cgroup_init+0x158/0x1c8 do_one_initcall+0x68/0x1d0 kernel_init_freeable+0x278/0x360 kernel_init+0x24/0x170 ret_from_kernel_thread+0x5c/0x74 Instruction dump: eb81ffe0 eba1ffe8 ebc1fff0 ebe1fff8 4e800020 3d230001 e9499a42 3d220004 3929acd8 794a1f24 7d295214 eac90100 <e9360000> 2fa90000 419eff74 3b200000 ---[ end trace 342f5208b00d01b6 ]--- This is a chicken and egg issue where the kernel try to get free memory when allocating per node data in mem_cgroup_init(), but in that path mem_cgroup_soft_limit_reclaim() is called which assumes that these data are allocated. As mem_cgroup_soft_limit_reclaim() is best effort, it should return when these data are not yet allocated. This patch also fixes potential null pointer access in mem_cgroup_remove_from_trees() and mem_cgroup_update_tree(). Link: http://lkml.kernel.org/r/1487856999-16581-2-git-send-email-ldufour@linux.vnet.ibm.com Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Balbir Singh <bsingharora@gmail.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

quarantine_remove_cache() frees all pending objects that belong to the cache, before we destroy the cache itself. However there are currently two possibilities how it can fail to do so. First, another thread can hold some of the objects from the cache in temp list in quarantine_put(). quarantine_put() has a windows of enabled interrupts, and on_each_cpu() in quarantine_remove_cache() can finish right in that window. These objects will be later freed into the destroyed cache. Then, quarantine_reduce() has the same problem. It grabs a batch of objects from the global quarantine, then unlocks quarantine_lock and then frees the batch. quarantine_remove_cache() can finish while some objects from the cache are still in the local to_free list in quarantine_reduce(). Fix the race with quarantine_put() by disabling interrupts for the whole duration of quarantine_put(). In combination with on_each_cpu() in quarantine_remove_cache() it ensures that quarantine_remove_cache() either sees the objects in the per-cpu list or in the global list. Fix the race with quarantine_reduce() by protecting quarantine_reduce() with srcu critical section and then doing synchronize_srcu() at the end of quarantine_remove_cache(). I've done some assessment of how good synchronize_srcu() works in this case. And on a 4 CPU VM I see that it blocks waiting for pending read critical sections in about 2-3% of cases. Which looks good to me. I suspect that these races are the root cause of some GPFs that I episodically hit. Previously I did not have any explanation for them. BUG: unable to handle kernel NULL pointer dereference at 00000000000000c8 IP: qlist_free_all+0x2e/0xc0 mm/kasan/quarantine.c:155 PGD 6aeea067 PUD 60ed7067 PMD 0 Oops: 0000 [#1] SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 0 PID: 13667 Comm: syz-executor2 Not tainted 4.10.0+ #60 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 task: ffff88005f948040 task.stack: ffff880069818000 RIP: 0010:qlist_free_all+0x2e/0xc0 mm/kasan/quarantine.c:155 RSP: 0018:ffff88006981f298 EFLAGS: 00010246 RAX: ffffea0000ffff00 RBX: 0000000000000000 RCX: ffffea0000ffff1f RDX: 0000000000000000 RSI: ffff88003fffc3e0 RDI: 0000000000000000 RBP: ffff88006981f2c0 R08: ffff88002fed7bd8 R09: 00000001001f000d R10: 00000000001f000d R11: ffff88006981f000 R12: ffff88003fffc3e0 R13: ffff88006981f2d0 R14: ffffffff81877fae R15: 0000000080000000 FS: 00007fb911a2d700(0000) GS:ffff88003ec00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000000000c8 CR3: 0000000060ed6000 CR4: 00000000000006f0 Call Trace: quarantine_reduce+0x10e/0x120 mm/kasan/quarantine.c:239 kasan_kmalloc+0xca/0xe0 mm/kasan/kasan.c:590 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:544 slab_post_alloc_hook mm/slab.h:456 [inline] slab_alloc_node mm/slub.c:2718 [inline] kmem_cache_alloc_node+0x1d3/0x280 mm/slub.c:2754 __alloc_skb+0x10f/0x770 net/core/skbuff.c:219 alloc_skb include/linux/skbuff.h:932 [inline] _sctp_make_chunk+0x3b/0x260 net/sctp/sm_make_chunk.c:1388 sctp_make_data net/sctp/sm_make_chunk.c:1420 [inline] sctp_make_datafrag_empty+0x208/0x360 net/sctp/sm_make_chunk.c:746 sctp_datamsg_from_user+0x7e8/0x11d0 net/sctp/chunk.c:266 sctp_sendmsg+0x2611/0x3970 net/sctp/socket.c:1962 inet_sendmsg+0x164/0x5b0 net/ipv4/af_inet.c:761 sock_sendmsg_nosec net/socket.c:633 [inline] sock_sendmsg+0xca/0x110 net/socket.c:643 SYSC_sendto+0x660/0x810 net/socket.c:1685 SyS_sendto+0x40/0x50 net/socket.c:1653 I am not sure about backporting. The bug is quite hard to trigger, I've seen it few times during our massive continuous testing (however, it could be cause of some other episodic stray crashes as it leads to memory corruption...). If it is triggered, the consequences are very bad -- almost definite bad memory corruption. The fix is non trivial and has chances of introducing new bugs. I am also not sure how actively people use KASAN on older releases. [dvyukov@google.com: - sorted includes[ Link: http://lkml.kernel.org/r/20170309094028.51088-1-dvyukov@google.com Link: http://lkml.kernel.org/r/20170308151532.5070-1-dvyukov@google.com Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Greg Thelen <gthelen@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit 5657933 ("treewide: Move dma_ops from struct dev_archdata into struct device") introduced a crash for macio devices, an example backtrace being: kernel BUG at ./include/linux/dma-mapping.h:465! Oops: Exception in kernel mode, sig: 5 [#1] ... NIP [c031ddb0] dmam_alloc_coherent+0x74/0x140 LR [c031de70] dmam_alloc_coherent+0x134/0x140 Call Trace: dmam_alloc_coherent+0x134/0x140 (unreliable) pata_macio_port_start+0x3c/0x8c ata_host_start.part.5+0xfc/0x208 ata_host_activate+0x128/0x154 pata_macio_common_init+0x2f0/0x538 pata_macio_attach+0xd8/0x180 macio_device_probe+0x5c/0xec driver_probe_device+0x21c/0x314 __driver_attach+0xcc/0xd0 bus_for_each_dev+0x68/0xb4 bus_add_driver+0x1dc/0x244 driver_register+0x88/0x130 pata_macio_init+0x5c/0x88 do_one_initcall+0x40/0x170 kernel_init_freeable+0x134/0x1d0 kernel_init+0x18/0x110 ret_from_kernel_thread+0x5c/0x64 This was caused by the device having NULL dma_ops, triggering the BUG_ON(). Previously the device inherited its dma_ops via the assignment to dev->ofdev.dev.archdata. However after commit 5657933 the dma_ops are moved into dev->ofdev.dev, and so they need to be explicitly copied. Fixes: 5657933 ("treewide: Move dma_ops from struct dev_archdata into struct device") Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net> Suggested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [mpe: Rewrite change log, add backtrace] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Yuval Mintz says: ==================== qed: Fixes series This address several different issues in qed. The more significant portions: Patch #1 would cause timeout when qedr utilizes the highest CIDs availble for it [or when future qede adapters would utilize queues in some constellations]. Patch #4 fixes a leak of mapped addresses; When iommu is enabled, offloaded storage protocols might eventually run out of resources and fail to map additional buffers. Patches #6,#7 were missing in the initial iSCSI infrastructure submissions, and would hamper qedi's stability when it reaches out-of-order scenarios. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>

Fix a bug in AFS read whereby the request page afs_read::index isn't incremented after calling ->page_done() if ->remain reaches 0, indicating that the data read is complete. Without this a NULL pointer exception happens when ->page_done() is called twice for the last page because the page clearing loop will call it also and afs_readpages_page_done() clears the current entry in the page list. BUG: unable to handle kernel NULL pointer dereference at (null) IP: afs_readpages_page_done+0x21/0xa4 [kafs] PGD 0 Oops: 0002 [#1] SMP Modules linked in: kafs(E) CPU: 2 PID: 3002 Comm: md5sum Tainted: G E 4.10.0-fscache #485 Hardware name: ASUS All Series/H97-PLUS, BIOS 2306 10/09/2014 task: ffff8804017d86c0 task.stack: ffff8803fc1d8000 RIP: 0010:afs_readpages_page_done+0x21/0xa4 [kafs] RSP: 0018:ffff8803fc1db978 EFLAGS: 00010282 RAX: ffff880405d39af8 RBX: 0000000000000000 RCX: ffff880407d83ed4 RDX: 0000000000000000 RSI: ffff880405d39a00 RDI: ffff880405c6f400 RBP: ffff8803fc1db988 R08: 0000000000000000 R09: 0000000000000001 R10: ffff8803fc1db820 R11: ffff88040cf56000 R12: ffff8804088f1780 R13: ffff8804017d86c0 R14: ffff8804088f1780 R15: 0000000000003840 FS: 00007f8154469700(0000) GS:ffff88041fb00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 00000004016ec000 CR4: 00000000001406e0 Call Trace: afs_deliver_fs_fetch_data+0x5b9/0x60e [kafs] ? afs_make_call+0x316/0x4e8 [kafs] ? afs_make_call+0x359/0x4e8 [kafs] afs_deliver_to_call+0x173/0x2e8 [kafs] ? afs_make_call+0x316/0x4e8 [kafs] afs_make_call+0x37a/0x4e8 [kafs] ? wake_up_q+0x4f/0x4f ? __init_waitqueue_head+0x36/0x49 afs_fs_fetch_data+0x21c/0x227 [kafs] ? afs_fs_fetch_data+0x21c/0x227 [kafs] afs_vnode_fetch_data+0xf3/0x1d2 [kafs] afs_readpages+0x314/0x3fd [kafs] __do_page_cache_readahead+0x208/0x2c5 ondemand_readahead+0x3a2/0x3b7 ? ondemand_readahead+0x3a2/0x3b7 page_cache_async_readahead+0x5e/0x67 generic_file_read_iter+0x23b/0x70c ? __inode_security_revalidate+0x2f/0x62 __vfs_read+0xc4/0xe8 vfs_read+0xd1/0x15a SyS_read+0x4c/0x89 do_syscall_64+0x80/0x191 entry_SYSCALL64_slow_path+0x25/0x25 Reported-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Marc Dionne <marc.dionne@auristor.com>

When iterating busy requests in timeout handler, if the STARTED flag of one request isn't set, that means the request is being processed in block layer or driver, and isn't submitted to hardware yet. In current implementation of blk_mq_check_expired(), if the request queue becomes dying, un-started requests are handled as being completed/freed immediately. This way is wrong, and can cause rq corruption or double allocation[1][2], when doing I/O and removing&resetting NVMe device at the sametime. This patch fixes several issues reported by Yi Zhang. [1]. oops log 1 [ 581.789754] ------------[ cut here ]------------ [ 581.789758] kernel BUG at block/blk-mq.c:374! [ 581.789760] invalid opcode: 0000 [#1] SMP [ 581.789761] Modules linked in: vfat fat ipmi_ssif intel_rapl sb_edac edac_core x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm nvme irqbypass crct10dif_pclmul nvme_core crc32_pclmul ghash_clmulni_intel intel_cstate ipmi_si mei_me ipmi_devintf intel_uncore sg ipmi_msghandler intel_rapl_perf iTCO_wdt mei iTCO_vendor_support mxm_wmi lpc_ich dcdbas shpchp pcspkr acpi_power_meter wmi nfsd auth_rpcgss nfs_acl lockd dm_multipath grace sunrpc ip_tables xfs libcrc32c sd_mod mgag200 i2c_algo_bit drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm ahci libahci crc32c_intel tg3 libata megaraid_sas i2c_core ptp fjes pps_core dm_mirror dm_region_hash dm_log dm_mod [ 581.789796] CPU: 1 PID: 1617 Comm: kworker/1:1H Not tainted 4.10.0.bz1420297+ #4 [ 581.789797] Hardware name: Dell Inc. PowerEdge R730xd/072T6D, BIOS 2.2.5 09/06/2016 [ 581.789804] Workqueue: kblockd blk_mq_timeout_work [ 581.789806] task: ffff8804721c8000 task.stack: ffffc90006ee4000 [ 581.789809] RIP: 0010:blk_mq_end_request+0x58/0x70 [ 581.789810] RSP: 0018:ffffc90006ee7d50 EFLAGS: 00010202 [ 581.789811] RAX: 0000000000000001 RBX: ffff8802e4195340 RCX: ffff88028e2f4b88 [ 581.789812] RDX: 0000000000001000 RSI: 0000000000001000 RDI: 0000000000000000 [ 581.789813] RBP: ffffc90006ee7d60 R08: 0000000000000003 R09: ffff88028e2f4b00 [ 581.789814] R10: 0000000000001000 R11: 0000000000000001 R12: 00000000fffffffb [ 581.789815] R13: ffff88042abe5780 R14: 000000000000002d R15: ffff88046fbdff80 [ 581.789817] FS: 0000000000000000(0000) GS:ffff88047fc00000(0000) knlGS:0000000000000000 [ 581.789818] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 581.789819] CR2: 00007f64f403a008 CR3: 000000014d078000 CR4: 00000000001406e0 [ 581.789820] Call Trace: [ 581.789825] blk_mq_check_expired+0x76/0x80 [ 581.789828] bt_iter+0x45/0x50 [ 581.789830] blk_mq_queue_tag_busy_iter+0xdd/0x1f0 [ 581.789832] ? blk_mq_rq_timed_out+0x70/0x70 [ 581.789833] ? blk_mq_rq_timed_out+0x70/0x70 [ 581.789840] ? __switch_to+0x140/0x450 [ 581.789841] blk_mq_timeout_work+0x88/0x170 [ 581.789845] process_one_work+0x165/0x410 [ 581.789847] worker_thread+0x137/0x4c0 [ 581.789851] kthread+0x101/0x140 [ 581.789853] ? rescuer_thread+0x3b0/0x3b0 [ 581.789855] ? kthread_park+0x90/0x90 [ 581.789860] ret_from_fork+0x2c/0x40 [ 581.789861] Code: 48 85 c0 74 0d 44 89 e6 48 89 df ff d0 5b 41 5c 5d c3 48 8b bb 70 01 00 00 48 85 ff 75 0f 48 89 df e8 7d f0 ff ff 5b 41 5c 5d c3 <0f> 0b e8 71 f0 ff ff 90 eb e9 0f 1f 40 00 66 2e 0f 1f 84 00 00 [ 581.789882] RIP: blk_mq_end_request+0x58/0x70 RSP: ffffc90006ee7d50 [ 581.789889] ---[ end trace bcaf03d9a14a0a70 ]--- [2]. oops log2 [ 6984.857362] BUG: unable to handle kernel NULL pointer dereference at 0000000000000010 [ 6984.857372] IP: nvme_queue_rq+0x6e6/0x8cd [nvme] [ 6984.857373] PGD 0 [ 6984.857374] [ 6984.857376] Oops: 0000 [#1] SMP [ 6984.857379] Modules linked in: ipmi_ssif vfat fat intel_rapl sb_edac edac_core x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel ipmi_si iTCO_wdt iTCO_vendor_support mxm_wmi ipmi_devintf intel_cstate sg dcdbas intel_uncore mei_me intel_rapl_perf mei pcspkr lpc_ich ipmi_msghandler shpchp acpi_power_meter wmi nfsd auth_rpcgss dm_multipath nfs_acl lockd grace sunrpc ip_tables xfs libcrc32c sd_mod mgag200 i2c_algo_bit drm_kms_helper syscopyarea sysfillrect crc32c_intel sysimgblt fb_sys_fops ttm nvme drm nvme_core ahci libahci i2c_core tg3 libata ptp megaraid_sas pps_core fjes dm_mirror dm_region_hash dm_log dm_mod [ 6984.857416] CPU: 7 PID: 1635 Comm: kworker/7:1H Not tainted 4.10.0-2.el7.bz1420297.x86_64 #1 [ 6984.857417] Hardware name: Dell Inc. PowerEdge R730xd/072T6D, BIOS 2.2.5 09/06/2016 [ 6984.857427] Workqueue: kblockd blk_mq_run_work_fn [ 6984.857429] task: ffff880476e3da00 task.stack: ffffc90002e90000 [ 6984.857432] RIP: 0010:nvme_queue_rq+0x6e6/0x8cd [nvme] [ 6984.857433] RSP: 0018:ffffc90002e93c50 EFLAGS: 00010246 [ 6984.857434] RAX: 0000000000000000 RBX: ffff880275646600 RCX: 0000000000001000 [ 6984.857435] RDX: 0000000000000fff RSI: 00000002fba2a000 RDI: ffff8804734e6950 [ 6984.857436] RBP: ffffc90002e93d30 R08: 0000000000002000 R09: 0000000000001000 [ 6984.857437] R10: 0000000000001000 R11: 0000000000000000 R12: ffff8804741d8000 [ 6984.857438] R13: 0000000000000040 R14: ffff880475649f80 R15: ffff8804734e6780 [ 6984.857439] FS: 0000000000000000(0000) GS:ffff88047fcc0000(0000) knlGS:0000000000000000 [ 6984.857440] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 6984.857442] CR2: 0000000000000010 CR3: 0000000001c09000 CR4: 00000000001406e0 [ 6984.857443] Call Trace: [ 6984.857451] ? mempool_free+0x2b/0x80 [ 6984.857455] ? bio_free+0x4e/0x60 [ 6984.857459] blk_mq_dispatch_rq_list+0xf5/0x230 [ 6984.857462] blk_mq_process_rq_list+0x133/0x170 [ 6984.857465] __blk_mq_run_hw_queue+0x8c/0xa0 [ 6984.857467] blk_mq_run_work_fn+0x12/0x20 [ 6984.857473] process_one_work+0x165/0x410 [ 6984.857475] worker_thread+0x137/0x4c0 [ 6984.857478] kthread+0x101/0x140 [ 6984.857480] ? rescuer_thread+0x3b0/0x3b0 [ 6984.857481] ? kthread_park+0x90/0x90 [ 6984.857489] ret_from_fork+0x2c/0x40 [ 6984.857490] Code: 8b bd 70 ff ff ff 89 95 50 ff ff ff 89 8d 58 ff ff ff 44 89 95 60 ff ff ff e8 b7 dd 12 e1 8b 95 50 ff ff ff 48 89 85 68 ff ff ff <4c> 8b 48 10 44 8b 58 18 8b 8d 58 ff ff ff 44 8b 95 60 ff ff ff [ 6984.857511] RIP: nvme_queue_rq+0x6e6/0x8cd [nvme] RSP: ffffc90002e93c50 [ 6984.857512] CR2: 0000000000000010 [ 6984.895359] ---[ end trace 2d7ceb528432bf83 ]--- Cc: stable@vger.kernel.org Reported-by: Yi Zhang <yizhan@redhat.com> Tested-by: Yi Zhang <yizhan@redhat.com> Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Ming Lei <tom.leiming@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com>

Dmitry reported a lockdep splat [1] (false positive) that we can fix by releasing the spinlock before calling icmp_send() from ip_expire() This is a false positive because sending an ICMP message can not possibly re-enter the IP frag engine. [1] [ INFO: possible circular locking dependency detected ] 4.10.0+ #29 Not tainted ------------------------------------------------------- modprobe/12392 is trying to acquire lock: (_xmit_ETHER#2){+.-...}, at: [<ffffffff837a8182>] spin_lock include/linux/spinlock.h:299 [inline] (_xmit_ETHER#2){+.-...}, at: [<ffffffff837a8182>] __netif_tx_lock include/linux/netdevice.h:3486 [inline] (_xmit_ETHER#2){+.-...}, at: [<ffffffff837a8182>] sch_direct_xmit+0x282/0x6d0 net/sched/sch_generic.c:180 but task is already holding lock: (&(&q->lock)->rlock){+.-...}, at: [<ffffffff8389a4d1>] spin_lock include/linux/spinlock.h:299 [inline] (&(&q->lock)->rlock){+.-...}, at: [<ffffffff8389a4d1>] ip_expire+0x51/0x6c0 net/ipv4/ip_fragment.c:201 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&(&q->lock)->rlock){+.-...}: validate_chain kernel/locking/lockdep.c:2267 [inline] __lock_acquire+0x2149/0x3430 kernel/locking/lockdep.c:3340 lock_acquire+0x2a1/0x630 kernel/locking/lockdep.c:3755 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x33/0x50 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:299 [inline] ip_defrag+0x3a2/0x4130 net/ipv4/ip_fragment.c:669 ip_check_defrag+0x4e3/0x8b0 net/ipv4/ip_fragment.c:713 packet_rcv_fanout+0x282/0x800 net/packet/af_packet.c:1459 deliver_skb net/core/dev.c:1834 [inline] dev_queue_xmit_nit+0x294/0xa90 net/core/dev.c:1890 xmit_one net/core/dev.c:2903 [inline] dev_hard_start_xmit+0x16b/0xab0 net/core/dev.c:2923 sch_direct_xmit+0x31f/0x6d0 net/sched/sch_generic.c:182 __dev_xmit_skb net/core/dev.c:3092 [inline] __dev_queue_xmit+0x13e5/0x1e60 net/core/dev.c:3358 dev_queue_xmit+0x17/0x20 net/core/dev.c:3423 neigh_resolve_output+0x6b9/0xb10 net/core/neighbour.c:1308 neigh_output include/net/neighbour.h:478 [inline] ip_finish_output2+0x8b8/0x15a0 net/ipv4/ip_output.c:228 ip_do_fragment+0x1d93/0x2720 net/ipv4/ip_output.c:672 ip_fragment.constprop.54+0x145/0x200 net/ipv4/ip_output.c:545 ip_finish_output+0x82d/0xe10 net/ipv4/ip_output.c:314 NF_HOOK_COND include/linux/netfilter.h:246 [inline] ip_output+0x1f0/0x7a0 net/ipv4/ip_output.c:404 dst_output include/net/dst.h:486 [inline] ip_local_out+0x95/0x170 net/ipv4/ip_output.c:124 ip_send_skb+0x3c/0xc0 net/ipv4/ip_output.c:1492 ip_push_pending_frames+0x64/0x80 net/ipv4/ip_output.c:1512 raw_sendmsg+0x26de/0x3a00 net/ipv4/raw.c:655 inet_sendmsg+0x164/0x5b0 net/ipv4/af_inet.c:761 sock_sendmsg_nosec net/socket.c:633 [inline] sock_sendmsg+0xca/0x110 net/socket.c:643 ___sys_sendmsg+0x4a3/0x9f0 net/socket.c:1985 __sys_sendmmsg+0x25c/0x750 net/socket.c:2075 SYSC_sendmmsg net/socket.c:2106 [inline] SyS_sendmmsg+0x35/0x60 net/socket.c:2101 do_syscall_64+0x2e8/0x930 arch/x86/entry/common.c:281 return_from_SYSCALL_64+0x0/0x7a -> #0 (_xmit_ETHER#2){+.-...}: check_prev_add kernel/locking/lockdep.c:1830 [inline] check_prevs_add+0xa8f/0x19f0 kernel/locking/lockdep.c:1940 validate_chain kernel/locking/lockdep.c:2267 [inline] __lock_acquire+0x2149/0x3430 kernel/locking/lockdep.c:3340 lock_acquire+0x2a1/0x630 kernel/locking/lockdep.c:3755 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x33/0x50 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:299 [inline] __netif_tx_lock include/linux/netdevice.h:3486 [inline] sch_direct_xmit+0x282/0x6d0 net/sched/sch_generic.c:180 __dev_xmit_skb net/core/dev.c:3092 [inline] __dev_queue_xmit+0x13e5/0x1e60 net/core/dev.c:3358 dev_queue_xmit+0x17/0x20 net/core/dev.c:3423 neigh_hh_output include/net/neighbour.h:468 [inline] neigh_output include/net/neighbour.h:476 [inline] ip_finish_output2+0xf6c/0x15a0 net/ipv4/ip_output.c:228 ip_finish_output+0xa29/0xe10 net/ipv4/ip_output.c:316 NF_HOOK_COND include/linux/netfilter.h:246 [inline] ip_output+0x1f0/0x7a0 net/ipv4/ip_output.c:404 dst_output include/net/dst.h:486 [inline] ip_local_out+0x95/0x170 net/ipv4/ip_output.c:124 ip_send_skb+0x3c/0xc0 net/ipv4/ip_output.c:1492 ip_push_pending_frames+0x64/0x80 net/ipv4/ip_output.c:1512 icmp_push_reply+0x372/0x4d0 net/ipv4/icmp.c:394 icmp_send+0x156c/0x1c80 net/ipv4/icmp.c:754 ip_expire+0x40e/0x6c0 net/ipv4/ip_fragment.c:239 call_timer_fn+0x241/0x820 kernel/time/timer.c:1268 expire_timers kernel/time/timer.c:1307 [inline] __run_timers+0x960/0xcf0 kernel/time/timer.c:1601 run_timer_softirq+0x21/0x80 kernel/time/timer.c:1614 __do_softirq+0x31f/0xbe7 kernel/softirq.c:284 invoke_softirq kernel/softirq.c:364 [inline] irq_exit+0x1cc/0x200 kernel/softirq.c:405 exiting_irq arch/x86/include/asm/apic.h:657 [inline] smp_apic_timer_interrupt+0x76/0xa0 arch/x86/kernel/apic/apic.c:962 apic_timer_interrupt+0x93/0xa0 arch/x86/entry/entry_64.S:707 __read_once_size include/linux/compiler.h:254 [inline] atomic_read arch/x86/include/asm/atomic.h:26 [inline] rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:350 [inline] __rcu_is_watching kernel/rcu/tree.c:1133 [inline] rcu_is_watching+0x83/0x110 kernel/rcu/tree.c:1147 rcu_read_lock_held+0x87/0xc0 kernel/rcu/update.c:293 radix_tree_deref_slot include/linux/radix-tree.h:238 [inline] filemap_map_pages+0x6d4/0x1570 mm/filemap.c:2335 do_fault_around mm/memory.c:3231 [inline] do_read_fault mm/memory.c:3265 [inline] do_fault+0xbd5/0x2080 mm/memory.c:3370 handle_pte_fault mm/memory.c:3600 [inline] __handle_mm_fault+0x1062/0x2cb0 mm/memory.c:3714 handle_mm_fault+0x1e2/0x480 mm/memory.c:3751 __do_page_fault+0x4f6/0xb60 arch/x86/mm/fault.c:1397 do_page_fault+0x54/0x70 arch/x86/mm/fault.c:1460 page_fault+0x28/0x30 arch/x86/entry/entry_64.S:1011 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&(&q->lock)->rlock); lock(_xmit_ETHER#2); lock(&(&q->lock)->rlock); lock(_xmit_ETHER#2); *** DEADLOCK *** 10 locks held by modprobe/12392: #0: (&mm->mmap_sem){++++++}, at: [<ffffffff81329758>] __do_page_fault+0x2b8/0xb60 arch/x86/mm/fault.c:1336 #1: (rcu_read_lock){......}, at: [<ffffffff8188cab6>] filemap_map_pages+0x1e6/0x1570 mm/filemap.c:2324 #2: (&(ptlock_ptr(page))->rlock#2){+.+...}, at: [<ffffffff81984a78>] spin_lock include/linux/spinlock.h:299 [inline] #2: (&(ptlock_ptr(page))->rlock#2){+.+...}, at: [<ffffffff81984a78>] pte_alloc_one_map mm/memory.c:2944 [inline] #2: (&(ptlock_ptr(page))->rlock#2){+.+...}, at: [<ffffffff81984a78>] alloc_set_pte+0x13b8/0x1b90 mm/memory.c:3072 #3: (((&q->timer))){+.-...}, at: [<ffffffff81627e72>] lockdep_copy_map include/linux/lockdep.h:175 [inline] #3: (((&q->timer))){+.-...}, at: [<ffffffff81627e72>] call_timer_fn+0x1c2/0x820 kernel/time/timer.c:1258 #4: (&(&q->lock)->rlock){+.-...}, at: [<ffffffff8389a4d1>] spin_lock include/linux/spinlock.h:299 [inline] #4: (&(&q->lock)->rlock){+.-...}, at: [<ffffffff8389a4d1>] ip_expire+0x51/0x6c0 net/ipv4/ip_fragment.c:201 #5: (rcu_read_lock){......}, at: [<ffffffff8389a633>] ip_expire+0x1b3/0x6c0 net/ipv4/ip_fragment.c:216 #6: (slock-AF_INET){+.-...}, at: [<ffffffff839b3313>] spin_trylock include/linux/spinlock.h:309 [inline] #6: (slock-AF_INET){+.-...}, at: [<ffffffff839b3313>] icmp_xmit_lock net/ipv4/icmp.c:219 [inline] #6: (slock-AF_INET){+.-...}, at: [<ffffffff839b3313>] icmp_send+0x803/0x1c80 net/ipv4/icmp.c:681 #7: (rcu_read_lock_bh){......}, at: [<ffffffff838ab9a1>] ip_finish_output2+0x2c1/0x15a0 net/ipv4/ip_output.c:198 #8: (rcu_read_lock_bh){......}, at: [<ffffffff836d1dee>] __dev_queue_xmit+0x23e/0x1e60 net/core/dev.c:3324 #9: (dev->qdisc_running_key ?: &qdisc_running_key){+.....}, at: [<ffffffff836d3a27>] dev_queue_xmit+0x17/0x20 net/core/dev.c:3423 stack backtrace: CPU: 0 PID: 12392 Comm: modprobe Not tainted 4.10.0+ #29 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x2ee/0x3ef lib/dump_stack.c:52 print_circular_bug+0x307/0x3b0 kernel/locking/lockdep.c:1204 check_prev_add kernel/locking/lockdep.c:1830 [inline] check_prevs_add+0xa8f/0x19f0 kernel/locking/lockdep.c:1940 validate_chain kernel/locking/lockdep.c:2267 [inline] __lock_acquire+0x2149/0x3430 kernel/locking/lockdep.c:3340 lock_acquire+0x2a1/0x630 kernel/locking/lockdep.c:3755 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x33/0x50 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:299 [inline] __netif_tx_lock include/linux/netdevice.h:3486 [inline] sch_direct_xmit+0x282/0x6d0 net/sched/sch_generic.c:180 __dev_xmit_skb net/core/dev.c:3092 [inline] __dev_queue_xmit+0x13e5/0x1e60 net/core/dev.c:3358 dev_queue_xmit+0x17/0x20 net/core/dev.c:3423 neigh_hh_output include/net/neighbour.h:468 [inline] neigh_output include/net/neighbour.h:476 [inline] ip_finish_output2+0xf6c/0x15a0 net/ipv4/ip_output.c:228 ip_finish_output+0xa29/0xe10 net/ipv4/ip_output.c:316 NF_HOOK_COND include/linux/netfilter.h:246 [inline] ip_output+0x1f0/0x7a0 net/ipv4/ip_output.c:404 dst_output include/net/dst.h:486 [inline] ip_local_out+0x95/0x170 net/ipv4/ip_output.c:124 ip_send_skb+0x3c/0xc0 net/ipv4/ip_output.c:1492 ip_push_pending_frames+0x64/0x80 net/ipv4/ip_output.c:1512 icmp_push_reply+0x372/0x4d0 net/ipv4/icmp.c:394 icmp_send+0x156c/0x1c80 net/ipv4/icmp.c:754 ip_expire+0x40e/0x6c0 net/ipv4/ip_fragment.c:239 call_timer_fn+0x241/0x820 kernel/time/timer.c:1268 expire_timers kernel/time/timer.c:1307 [inline] __run_timers+0x960/0xcf0 kernel/time/timer.c:1601 run_timer_softirq+0x21/0x80 kernel/time/timer.c:1614 __do_softirq+0x31f/0xbe7 kernel/softirq.c:284 invoke_softirq kernel/softirq.c:364 [inline] irq_exit+0x1cc/0x200 kernel/softirq.c:405 exiting_irq arch/x86/include/asm/apic.h:657 [inline] smp_apic_timer_interrupt+0x76/0xa0 arch/x86/kernel/apic/apic.c:962 apic_timer_interrupt+0x93/0xa0 arch/x86/entry/entry_64.S:707 RIP: 0010:__read_once_size include/linux/compiler.h:254 [inline] RIP: 0010:atomic_read arch/x86/include/asm/atomic.h:26 [inline] RIP: 0010:rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:350 [inline] RIP: 0010:__rcu_is_watching kernel/rcu/tree.c:1133 [inline] RIP: 0010:rcu_is_watching+0x83/0x110 kernel/rcu/tree.c:1147 RSP: 0000:ffff8801c391f120 EFLAGS: 00000a03 ORIG_RAX: ffffffffffffff10 RAX: dffffc0000000000 RBX: ffff8801c391f148 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 000055edd4374000 RDI: ffff8801dbe1ae0c RBP: ffff8801c391f1a0 R08: 0000000000000002 R09: 0000000000000000 R10: dffffc0000000000 R11: 0000000000000002 R12: 1ffff10038723e25 R13: ffff8801dbe1ae00 R14: ffff8801c391f680 R15: dffffc0000000000 </IRQ> rcu_read_lock_held+0x87/0xc0 kernel/rcu/update.c:293 radix_tree_deref_slot include/linux/radix-tree.h:238 [inline] filemap_map_pages+0x6d4/0x1570 mm/filemap.c:2335 do_fault_around mm/memory.c:3231 [inline] do_read_fault mm/memory.c:3265 [inline] do_fault+0xbd5/0x2080 mm/memory.c:3370 handle_pte_fault mm/memory.c:3600 [inline] __handle_mm_fault+0x1062/0x2cb0 mm/memory.c:3714 handle_mm_fault+0x1e2/0x480 mm/memory.c:3751 __do_page_fault+0x4f6/0xb60 arch/x86/mm/fault.c:1397 do_page_fault+0x54/0x70 arch/x86/mm/fault.c:1460 page_fault+0x28/0x30 arch/x86/entry/entry_64.S:1011 RIP: 0033:0x7f83172f2786 RSP: 002b:00007fffe859ae80 EFLAGS: 00010293 RAX: 000055edd4373040 RBX: 00007f83175111c8 RCX: 000055edd4373238 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007f8317510970 RBP: 00007fffe859afd0 R08: 0000000000000009 R09: 0000000000000000 R10: 0000000000000064 R11: 0000000000000000 R12: 000055edd4373040 R13: 0000000000000000 R14: 00007fffe859afe8 R15: 0000000000000000 Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>

this fix aims to fix dereferencing of a mirror in an error state when MDS returns unsupported DS type (IOW, not v3), which causes the following oops: [ 220.370709] BUG: unable to handle kernel NULL pointer dereference at 0000000000000065 [ 220.370842] IP: ff_layout_mirror_valid+0x2d/0x110 [nfs_layout_flexfiles] [ 220.370920] PGD 0 [ 220.370972] Oops: 0000 [#1] SMP [ 220.371013] Modules linked in: nfnetlink_queue nfnetlink_log bluetooth nfs_layout_flexfiles rpcsec_gss_krb5 nfsv4 dns_resolver nfs fscache nf_conntrack_netbios_ns nf_conntrack_broadcast xt_CT ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 xt_conntrack ip_set nfnetlink ebtable_nat ebtable_broute bridge stp llc ip6table_raw ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_security iptable_raw iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack libcrc32c iptable_mangle iptable_security ebtable_filter ebtables ip6table_filter ip6_tables binfmt_misc intel_rapl x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel btrfs kvm arc4 snd_hda_codec_hdmi iwldvm irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel intel_cstate mac80211 xor uvcvideo [ 220.371814] videobuf2_vmalloc videobuf2_memops snd_hda_codec_idt mei_wdt videobuf2_v4l2 snd_hda_codec_generic iTCO_wdt ppdev videobuf2_core iTCO_vendor_support dell_rbtn dell_wmi iwlwifi sparse_keymap dell_laptop dell_smbios snd_hda_intel dcdbas videodev snd_hda_codec dell_smm_hwmon snd_hda_core media cfg80211 intel_uncore snd_hwdep raid6_pq snd_seq intel_rapl_perf snd_seq_device joydev i2c_i801 rfkill lpc_ich snd_pcm parport_pc mei_me parport snd_timer dell_smo8800 mei snd shpchp soundcore tpm_tis tpm_tis_core tpm nfsd auth_rpcgss nfs_acl lockd grace sunrpc i915 nouveau mxm_wmi ttm i2c_algo_bit drm_kms_helper crc32c_intel e1000e drm sdhci_pci firewire_ohci sdhci serio_raw mmc_core firewire_core ptp crc_itu_t pps_core wmi fjes video [ 220.372568] CPU: 7 PID: 4988 Comm: cat Not tainted 4.10.5-200.fc25.x86_64 #1 [ 220.372647] Hardware name: Dell Inc. Latitude E6520/0J4TFW, BIOS A06 07/11/2011 [ 220.372729] task: ffff94791f6ea580 task.stack: ffffb72b88c0c000 [ 220.372802] RIP: 0010:ff_layout_mirror_valid+0x2d/0x110 [nfs_layout_flexfiles] [ 220.372883] RSP: 0018:ffffb72b88c0f970 EFLAGS: 00010246 [ 220.372945] RAX: 0000000000000000 RBX: ffff9479015ca600 RCX: ffffffffffffffed [ 220.373025] RDX: ffffffffffffffed RSI: ffff9479753dc980 RDI: 0000000000000000 [ 220.373104] RBP: ffffb72b88c0f988 R08: 000000000001c980 R09: ffffffffc0ea6112 [ 220.373184] R10: ffffef17477d9640 R11: ffff9479753dd6c0 R12: ffff9479211c7440 [ 220.373264] R13: ffff9478f45b7790 R14: 0000000000000001 R15: ffff9479015ca600 [ 220.373345] FS: 00007f555fa3e700(0000) GS:ffff9479753c0000(0000) knlGS:0000000000000000 [ 220.373435] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 220.373506] CR2: 0000000000000065 CR3: 0000000196044000 CR4: 00000000000406e0 [ 220.373586] Call Trace: [ 220.373627] nfs4_ff_layout_prepare_ds+0x5e/0x200 [nfs_layout_flexfiles] [ 220.373708] ff_layout_pg_init_read+0x81/0x160 [nfs_layout_flexfiles] [ 220.373806] __nfs_pageio_add_request+0x11f/0x4a0 [nfs] [ 220.373886] ? nfs_create_request.part.14+0x37/0x330 [nfs] [ 220.373967] nfs_pageio_add_request+0xb2/0x260 [nfs] [ 220.374042] readpage_async_filler+0xaf/0x280 [nfs] [ 220.374103] read_cache_pages+0xef/0x1b0 [ 220.374166] ? nfs_read_completion+0x210/0x210 [nfs] [ 220.374239] nfs_readpages+0x129/0x200 [nfs] [ 220.374293] __do_page_cache_readahead+0x1d0/0x2f0 [ 220.374352] ondemand_readahead+0x17d/0x2a0 [ 220.374403] page_cache_sync_readahead+0x2e/0x50 [ 220.374460] generic_file_read_iter+0x6c8/0x950 [ 220.374532] ? nfs_mapping_need_revalidate_inode+0x17/0x40 [nfs] [ 220.374617] nfs_file_read+0x6e/0xc0 [nfs] [ 220.374670] __vfs_read+0xe2/0x150 [ 220.374715] vfs_read+0x96/0x130 [ 220.374758] SyS_read+0x55/0xc0 [ 220.374801] entry_SYSCALL_64_fastpath+0x1a/0xa9 [ 220.374856] RIP: 0033:0x7f555f570bd0 [ 220.374900] RSP: 002b:00007ffeb73e1b38 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 [ 220.374986] RAX: ffffffffffffffda RBX: 00007f555f839ae0 RCX: 00007f555f570bd0 [ 220.375066] RDX: 0000000000020000 RSI: 00007f555fa41000 RDI: 0000000000000003 [ 220.375145] RBP: 0000000000021010 R08: ffffffffffffffff R09: 0000000000000000 [ 220.375226] R10: 00007f555fa40010 R11: 0000000000000246 R12: 0000000000022000 [ 220.375305] R13: 0000000000021010 R14: 0000000000001000 R15: 0000000000002710 [ 220.375386] Code: 66 66 90 55 48 89 e5 41 54 53 49 89 fc 48 83 ec 08 48 85 f6 74 2e 48 8b 4e 30 48 89 f3 48 81 f9 00 f0 ff ff 77 1e 48 85 c9 74 15 <48> 83 79 78 00 b8 01 00 00 00 74 2c 48 83 c4 08 5b 41 5c 5d c3 [ 220.375653] RIP: ff_layout_mirror_valid+0x2d/0x110 [nfs_layout_flexfiles] RSP: ffffb72b88c0f970 [ 220.375748] CR2: 0000000000000065 [ 220.403538] ---[ end trace bcdca752211b7da9 ]--- Signed-off-by: Tigran Mkrtchyan <tigran.mkrtchyan@desy.de> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

I found that calling page migration for ksm pages causes the following bug: page:ffffea0004d51180 count:2 mapcount:2 mapping:ffff88013c785141 index:0x913 flags: 0x57ffffc0040068(uptodate|lru|active|swapbacked) raw: 0057ffffc0040068 ffff88013c785141 0000000000000913 0000000200000001 raw: ffffea0004d5f9e0 ffffea0004d53f60 0000000000000000 ffff88007d81b800 page dumped because: VM_BUG_ON_PAGE(!PageLocked(page)) page->mem_cgroup:ffff88007d81b800 ------------[ cut here ]------------ kernel BUG at /src/linux-dev/mm/rmap.c:1086! invalid opcode: 0000 [#1] SMP Modules linked in: ppdev parport_pc virtio_balloon i2c_piix4 pcspkr parport i2c_core acpi_cpufreq ip_tables xfs libcrc32c ata_generic pata_acpi ata_piix 8139too libata virtio_blk 8139cp crc32c_intel mii virtio_pci virtio_ring serio_raw virtio floppy dm_mirror dm_region_hash dm_log dm_mod CPU: 0 PID: 3162 Comm: bash Not tainted 4.11.0-rc2-mm1+ #1 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 RIP: 0010:do_page_add_anon_rmap+0x1ba/0x260 RSP: 0018:ffffc90002473b30 EFLAGS: 00010282 RAX: 0000000000000021 RBX: ffffea0004d51180 RCX: 0000000000000006 RDX: 0000000000000000 RSI: 0000000000000082 RDI: ffff88007dc0dfe0 RBP: ffffc90002473b58 R08: 00000000fffffffe R09: 00000000000001c1 R10: 0000000000000005 R11: 00000000000001c0 R12: ffff880139ab3d80 R13: 0000000000000000 R14: 0000700000000200 R15: 0000160000000000 FS: 00007f5195f50740(0000) GS:ffff88007dc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd450287000 CR3: 000000007a08e000 CR4: 00000000001406f0 Call Trace: page_add_anon_rmap+0x18/0x20 remove_migration_pte+0x220/0x2c0 rmap_walk_ksm+0x143/0x220 rmap_walk+0x55/0x60 remove_migration_ptes+0x53/0x80 migrate_pages+0x8ed/0xb60 soft_offline_page+0x309/0x8d0 store_soft_offline_page+0xaf/0xf0 dev_attr_store+0x18/0x30 sysfs_kf_write+0x3a/0x50 kernfs_fop_write+0xff/0x180 __vfs_write+0x37/0x160 vfs_write+0xb2/0x1b0 SyS_write+0x55/0xc0 do_syscall_64+0x67/0x180 entry_SYSCALL64_slow_path+0x25/0x25 RIP: 0033:0x7f51956339e0 RSP: 002b:00007ffcfa0dffc8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000000000000000c RCX: 00007f51956339e0 RDX: 000000000000000c RSI: 00007f5195f53000 RDI: 0000000000000001 RBP: 00007f5195f53000 R08: 000000000000000a R09: 00007f5195f50740 R10: 000000000000000b R11: 0000000000000246 R12: 00007f5195907400 R13: 000000000000000c R14: 0000000000000001 R15: 0000000000000000 Code: fe ff ff 48 81 c2 00 02 00 00 48 89 55 d8 e8 2e c3 fd ff 48 8b 55 d8 e9 42 ff ff ff 48 c7 c6 e0 52 a1 81 48 89 df e8 46 ad fe ff <0f> 0b 48 83 e8 01 e9 7f fe ff ff 48 83 e8 01 e9 96 fe ff ff 48 RIP: do_page_add_anon_rmap+0x1ba/0x260 RSP: ffffc90002473b30 ---[ end trace a679d00f4af2df48 ]--- Kernel panic - not syncing: Fatal exception Kernel Offset: disabled ---[ end Kernel panic - not syncing: Fatal exception The problem is in the following lines: new = page - pvmw.page->index + linear_page_index(vma, pvmw.address); The 'new' is calculated with 'page' which is given by the caller as a destination page and some offset adjustment for thp. But this doesn't properly work for ksm pages because pvmw.page->index doesn't change for each address but linear_page_index() changes, which means that 'new' points to different pages for each addresses backed by the ksm page. As a result, we try to set totally unrelated pages as destination pages, and that causes kernel crash. This patch fixes the miscalculation and makes ksm page migration work fine. Fixes: 3fe8796 ("mm: convert remove_migration_pte() to use page_vma_mapped_walk()") Link: http://lkml.kernel.org/r/1489717683-29905-1-git-send-email-n-horiguchi@ah.jp.nec.com Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

…e_pmd() I found the race condition which triggers the following bug when move_pages() and soft offline are called on a single hugetlb page concurrently. Soft offlining page 0x119400 at 0x700000000000 BUG: unable to handle kernel paging request at ffffea0011943820 IP: follow_huge_pmd+0x143/0x190 PGD 7ffd2067 PUD 7ffd1067 PMD 0 [61163.582052] Oops: 0000 [#1] SMP Modules linked in: binfmt_misc ppdev virtio_balloon parport_pc pcspkr i2c_piix4 parport i2c_core acpi_cpufreq ip_tables xfs libcrc32c ata_generic pata_acpi virtio_blk 8139too crc32c_intel ata_piix serio_raw libata virtio_pci 8139cp virtio_ring virtio mii floppy dm_mirror dm_region_hash dm_log dm_mod [last unloaded: cap_check] CPU: 0 PID: 22573 Comm: iterate_numa_mo Tainted: P OE 4.11.0-rc2-mm1+ #2 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 RIP: 0010:follow_huge_pmd+0x143/0x190 RSP: 0018:ffffc90004bdbcd0 EFLAGS: 00010202 RAX: 0000000465003e80 RBX: ffffea0004e34d30 RCX: 00003ffffffff000 RDX: 0000000011943800 RSI: 0000000000080001 RDI: 0000000465003e80 RBP: ffffc90004bdbd18 R08: 0000000000000000 R09: ffff880138d34000 R10: ffffea0004650000 R11: 0000000000c363b0 R12: ffffea0011943800 R13: ffff8801b8d34000 R14: ffffea0000000000 R15: 000077ff80000000 FS: 00007fc977710740(0000) GS:ffff88007dc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffea0011943820 CR3: 000000007a746000 CR4: 00000000001406f0 Call Trace: follow_page_mask+0x270/0x550 SYSC_move_pages+0x4ea/0x8f0 SyS_move_pages+0xe/0x10 do_syscall_64+0x67/0x180 entry_SYSCALL64_slow_path+0x25/0x25 RIP: 0033:0x7fc976e03949 RSP: 002b:00007ffe72221d88 EFLAGS: 00000246 ORIG_RAX: 0000000000000117 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc976e03949 RDX: 0000000000c22390 RSI: 0000000000001400 RDI: 0000000000005827 RBP: 00007ffe72221e00 R08: 0000000000c2c3a0 R09: 0000000000000004 R10: 0000000000c363b0 R11: 0000000000000246 R12: 0000000000400650 R13: 00007ffe72221ee0 R14: 0000000000000000 R15: 0000000000000000 Code: 81 e4 ff ff 1f 00 48 21 c2 49 c1 ec 0c 48 c1 ea 0c 4c 01 e2 49 bc 00 00 00 00 00 ea ff ff 48 c1 e2 06 49 01 d4 f6 45 bc 04 74 90 <49> 8b 7c 24 20 40 f6 c7 01 75 2b 4c 89 e7 8b 47 1c 85 c0 7e 2a RIP: follow_huge_pmd+0x143/0x190 RSP: ffffc90004bdbcd0 CR2: ffffea0011943820 ---[ end trace e4f81353a2d23232 ]--- Kernel panic - not syncing: Fatal exception Kernel Offset: disabled This bug is triggered when pmd_present() returns true for non-present hugetlb, so fixing the present check in follow_huge_pmd() prevents it. Using pmd_present() to determine present/non-present for hugetlb is not correct, because pmd_present() checks multiple bits (not only _PAGE_PRESENT) for historical reason and it can misjudge hugetlb state. Fixes: e66f17f ("mm/hugetlb: take page table lock in follow_huge_pmd()") Link: http://lkml.kernel.org/r/1490149898-20231-1-git-send-email-n-horiguchi@ah.jp.nec.com Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Hugh Dickins <hughd@google.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com> Cc: <stable@vger.kernel.org> [4.0+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Fix a crash from dereferencing a NULL dw_pcie_ops pointer. For example, on ARTPEC-6: Unable to handle kernel NULL pointer dereference at virtual address 00000004 pgd = c0204000 [00000004] *pgd=00000000 Internal error: Oops: 5 [#1] SMP ARM Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.11.0-rc3-next-20170321 #1 Hardware name: Axis ARTPEC-6 Platform task: db098000 task.stack: db096000 PC is at dw_pcie_writel_dbi+0x2c/0xd0 Prior to 442ec4c ("PCI: dwc: all: Split struct pcie_port into host-only and core structures"), every driver had a struct pcie_host_ops with function pointers, typically used as: if (pp->ops->readl_rc) return pp->ops->readl_rc(...); 442ec4c split struct pcie_host_ops into two pieces: struct dw_pcie_host_ops and struct dw_pcie_ops, so the above became: if (pci->ops->readl_dbi) return pci->ops->readl_dbi(...); But pcie-artpec6.c and pcie-designware-plat.c don't need the dw_pcie_ops pointers and didn't supply a pci->ops struct, which leads to NULL pointer dereferences. Supply an empty struct dw_pcie_ops to avoid the NULL pointer dereferences. [bhelgaas: changelog] Fixes: 442ec4c ("PCI: dwc: all: Split struct pcie_port into host-only and core structures") Signed-off-by: Niklas Cassel <niklas.cassel@axis.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Kishon Vijay Abraham I <kishon@ti.com> Acked-by: Joao Pinto <jpinto@synopsys.com>

…te() This commit moves sparc64's prototype of pmd_write() outside of the CONFIG_TRANSPARENT_HUGEPAGE ifdef. In 2013, commit a7b9403 ("sparc64: Encode huge PMDs using PTE encoding.") exposed a path where pmd_write() could be called without CONFIG_TRANSPARENT_HUGEPAGE defined. This can result in the panic below. The diff is awkward to read, but the changes are straightforward. pmd_write() was moved outside of #ifdef CONFIG_TRANSPARENT_HUGEPAGE. Also, __HAVE_ARCH_PMD_WRITE was defined. kernel BUG at include/asm-generic/pgtable.h:576! \|/ ____ \|/ "@'/ .. \`@" /_| \__/ |_\ \__U_/ oracle_8114_cdb(8114): Kernel bad sw trap 5 [#1] CPU: 120 PID: 8114 Comm: oracle_8114_cdb Not tainted 4.1.12-61.7.1.el6uek.rc1.sparc64 #1 task: fff8400700a24d60 ti: fff8400700bc4000 task.ti: fff8400700bc4000 TSTATE: 0000004411e01607 TPC: 00000000004609f8 TNPC: 00000000004609fc Y: 00000005 Not tainted TPC: <gup_huge_pmd+0x198/0x1e0> g0: 000000000001c000 g1: 0000000000ef3954 g2: 0000000000000000 g3: 0000000000000001 g4: fff8400700a24d60 g5: fff8001fa5c10000 g6: fff8400700bc4000 g7: 0000000000000720 o0: 0000000000bc5058 o1: 0000000000000240 o2: 0000000000006000 o3: 0000000000001c00 o4: 0000000000000000 o5: 0000048000080000 sp: fff8400700bc6ab1 ret_pc: 00000000004609f0 RPC: <gup_huge_pmd+0x190/0x1e0> l0: fff8400700bc74fc l1: 0000000000020000 l2: 0000000000002000 l3: 0000000000000000 l4: fff8001f93250950 l5: 000000000113f800 l6: 0000000000000004 l7: 0000000000000000 i0: fff8400700ca46a0 i1: bd0000085e800453 i2: 000000026a0c4000 i3: 000000026a0c6000 i4: 0000000000000001 i5: fff800070c958de8 i6: fff8400700bc6b61 i7: 0000000000460dd0 I7: <gup_pud_range+0x170/0x1a0> Call Trace: [0000000000460dd0] gup_pud_range+0x170/0x1a0 [0000000000460e84] get_user_pages_fast+0x84/0x120 [00000000006f5a18] iov_iter_get_pages+0x98/0x240 [00000000005fa744] do_direct_IO+0xf64/0x1e00 [00000000005fbbc0] __blockdev_direct_IO+0x360/0x15a0 [00000000101f74fc] ext4_ind_direct_IO+0xdc/0x400 [ext4] [00000000101af690] ext4_ext_direct_IO+0x1d0/0x2c0 [ext4] [00000000101af86c] ext4_direct_IO+0xec/0x220 [ext4] [0000000000553bd4] generic_file_read_iter+0x114/0x140 [00000000005bdc2c] __vfs_read+0xac/0x100 [00000000005bf254] vfs_read+0x54/0x100 [00000000005bf368] SyS_pread64+0x68/0x80 Signed-off-by: Tom Hromatka <tom.hromatka@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>

Without this fix (and another to the userspace component itself described later), the kernel will be unable to process any OrangeFS requests after the userspace component is restarted (due to a crash or at the administrator's behest). The bug here is that inside orangefs_remount, the orangefs_request_mutex is locked. When the userspace component restarts while the filesystem is mounted, it sends a ORANGEFS_DEV_REMOUNT_ALL ioctl to the device, which causes the kernel to send it a few requests aimed at synchronizing the state between the two. While this is happening the orangefs_request_mutex is locked to prevent any other requests going through. This is only half of the bugfix. The other half is in the userspace component which outright ignores(!) requests made before it considers the filesystem remounted, which is after the ioctl returns. Of course the ioctl doesn't return until after the userspace component responds to the request it ignores. The userspace component has been changed to allow ORANGEFS_VFS_OP_FEATURES regardless of the mount status. Mike Marshall says: "I've tested this patch against the fixed userspace part. This patch is real important, I hope it can make it into 4.11... Here's what happens when the userspace daemon is restarted, without the patch: ============================================= [ INFO: possible recursive locking detected ] [ 4.10.0-00007-ge98bdb3 #1 Not tainted ] --------------------------------------------- pvfs2-client-co/29032 is trying to acquire lock: (orangefs_request_mutex){+.+.+.}, at: service_operation+0x3c7/0x7b0 [orangefs] but task is already holding lock: (orangefs_request_mutex){+.+.+.}, at: dispatch_ioctl_command+0x1bf/0x330 [orangefs] CPU: 0 PID: 29032 Comm: pvfs2-client-co Not tainted 4.10.0-00007-ge98bdb3 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.3-1.fc25 04/01/2014 Call Trace: __lock_acquire+0x7eb/0x1290 lock_acquire+0xe8/0x1d0 mutex_lock_killable_nested+0x6f/0x6e0 service_operation+0x3c7/0x7b0 [orangefs] orangefs_remount+0xea/0x150 [orangefs] dispatch_ioctl_command+0x227/0x330 [orangefs] orangefs_devreq_ioctl+0x29/0x70 [orangefs] do_vfs_ioctl+0xa3/0x6e0 SyS_ioctl+0x79/0x90" Signed-off-by: Martin Brandenburg <martin@omnibond.com> Acked-by: Mike Marshall <hubcap@omnibond.com> Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

We need to initialize qedf->fipvlan_compl in __qedf_probe so that if we receive an unsolicited FIP VLAN response, the system doesn't crash due to trying to complete an uninitialized completion. Also add a check to see if there are any waiters on the completion so we don't inadvertantly kick start the discovery process due to the unsolicited frame. Fixed the crash: <1>BUG: unable to handle kernel NULL pointer dereference at (null) <1>IP: [<ffffffff8105ed71>] __wake_up_common+0x31/0x90 <4>PGD 0 <4>Oops: 0000 [#1] SMP <4>last sysfs file: /sys/devices/system/cpu/online <4>CPU 7 <4>Modules linked in: autofs4 nfs lockd fscache auth_rpcgss nfs_acl sunrpc target_core_iblock target_core_file target_core_pscsi target_core_mod configfs bnx2fc cnic fcoe 8021q garp stp llc ipt_REJECT nf_conntrack_ipv4 nf_defrag_ipv4 iptable_filter ip_tables ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables ipv6 vfat fat uinput ipmi_devintf microcode power_meter acpi_ipmi ipmi_si ipmi_msghandler iTCO_wdt iTCO_vendor_support dcdbas sg joydev sb_edac edac_core lpc_ich mfd_core shpchp tg3 ptp pps_core ext4 jbd2 mbcache sr_mod cdrom sd_mod crc_t10dif qedi(U) iscsi_boot_sysfs libiscsi scsi_transport_iscsi uio qedf(U) libfcoe libfc scsi_transport_fc scsi_tgt qede(U) qed(U) ahci megaraid_sas wmi dm_mirror dm_region_hash dm_log dm_mod [last unloaded: speedstep_lib] <4> <4>Pid: 1485, comm: qedf_11_ll2 Not tainted 2.6.32-642.el6.x86_64 #1 Dell Inc. PowerEdge R730/0599V5 <4>RIP: 0010:[<ffffffff8105ed71>] [<ffffffff8105ed71>] __wake_up_common+0x31/0x90 <4>RSP: 0018:ffff881068a83d50 EFLAGS: 00010086 <4>RAX: ffffffffffffffe8 RBX: ffff88106bf42de0 RCX: 0000000000000000 <4>RDX: 0000000000000000 RSI: 0000000000000003 RDI: ffff88106bf42de0 <4>RBP: ffff881068a83d90 R08: 0000000000000000 R09: 00000000fffffffe <4>R10: 0000000000000000 R11: 000000000000000b R12: 0000000000000286 <4>R13: ffff88106bf42de8 R14: 0000000000000000 R15: 0000000000000000 <4>FS: 0000000000000000(0000) GS:ffff88089c460000(0000) knlGS:0000000000000000 <4>CS: 0010 DS: 0018 ES: 0018 CR0: 000000008005003b <4>CR2: 0000000000000000 CR3: 0000000001a8d000 CR4: 00000000001407e0 <4>DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 <4>DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 <4>Process qedf_11_ll2 (pid: 1485, threadinfo ffff881068a80000, task ffff881068a70040) <4>Stack: <4> ffff88106ef00090 0000000300000001 ffff881068a83d90 ffff88106bf42de0 <4><d> 0000000000000286 ffff88106bf42dd8 ffff88106bf40a50 0000000000000002 <4><d> ffff881068a83dc0 ffffffff810634c7 ffff881000000003 000000000000000b <4>Call Trace: <4> [<ffffffff810634c7>] complete+0x47/0x60 <4> [<ffffffffa01d37e7>] qedf_fip_recv+0x1c7/0x450 [qedf] <4> [<ffffffffa01cb3cb>] qedf_ll2_recv_thread+0x33b/0x510 [qedf] <4> [<ffffffffa01cb090>] ? qedf_ll2_recv_thread+0x0/0x510 [qedf] <4> [<ffffffff810a662e>] kthread+0x9e/0xc0 <4> [<ffffffff8100c28a>] child_rip+0xa/0x20 <4> [<ffffffff810a6590>] ? kthread+0x0/0xc0 <4> [<ffffffff8100c280>] ? child_rip+0x0/0x20 <4>Code: 41 56 41 55 41 54 53 48 83 ec 18 0f 1f 44 00 00 89 75 cc 89 55 c8 4c 8d 6f 08 48 8b 57 08 41 89 cf 4d 89 c6 48 8d 42 e8 49 39 d5 <48> 8b 58 18 74 3f 48 83 eb 18 eb 0a 0f 1f 00 48 89 d8 48 8d 5a <1>RIP [<ffffffff8105ed71>] __wake_up_common+0x31/0x90 <4> RSP <ffff881068a83d50> <4>CR2: 0000000000000000 Signed-off-by: Chad Dupuis <chad.dupuis@cavium.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

mipsxx_pmu_handle_shared_irq() calls irq_work_run() while holding the pmuint_rwlock for read. irq_work_run() can, via perf_pending_event(), call try_to_wake_up() which can try to take rq->lock. However, perf can also call perf_pmu_enable() (and thus take the pmuint_rwlock for write) while holding the rq->lock, from finish_task_switch() via perf_event_context_sched_in(). This leads to an ABBA deadlock: PID: 3855 TASK: 8f7ce288 CPU: 2 COMMAND: "process" #0 [89c39ac8] __delay at 803b5be4 #1 [89c39ac8] do_raw_spin_lock at 8008fdcc #2 [89c39af8] try_to_wake_up at 8006e47c #3 [89c39b38] pollwake at 8018eab0 #4 [89c39b68] __wake_up_common at 800879f4 #5 [89c39b98] __wake_up at 800880e4 #6 [89c39bc8] perf_event_wakeup at 8012109c #7 [89c39be8] perf_pending_event at 80121184 #8 [89c39c08] irq_work_run_list at 801151f0 #9 [89c39c38] irq_work_run at 80115274 #10 [89c39c50] mipsxx_pmu_handle_shared_irq at 8002cc7c PID: 1481 TASK: 8eaac6a8 CPU: 3 COMMAND: "process" #0 [8de7f900] do_raw_write_lock at 800900e0 #1 [8de7f918] perf_event_context_sched_in at 80122310 #2 [8de7f938] __perf_event_task_sched_in at 80122608 #3 [8de7f958] finish_task_switch at 8006b8a4 #4 [8de7f998] __schedule at 805e4dc4 #5 [8de7f9f8] schedule at 805e5558 #6 [8de7fa10] schedule_hrtimeout_range_clock at 805e9984 #7 [8de7fa70] poll_schedule_timeout at 8018e8f8 #8 [8de7fa88] do_select at 8018f338 #9 [8de7fd88] core_sys_select at 8018f5cc #10 [8de7fee0] sys_select at 8018f854 #11 [8de7ff28] syscall_common at 80028fc8 The lock seems to be there to protect the hardware counters so there is no need to hold it across irq_work_run(). Signed-off-by: Rabin Vincent <rabinv@axis.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

The following UAF was triggered when running fstests generic/072 with KASAN enabled against Windows Server 2022 and mount options 'multichannel,max_channels=2,vers=3.1.1,mfsymlinks,noperm' BUG: KASAN: slab-use-after-free in smb2_query_info_compound+0x423/0x6d0 [cifs] Read of size 8 at addr ffff888014941048 by task xfs_io/27534 CPU: 0 PID: 27534 Comm: xfs_io Not tainted 6.6.0-rc7 #1 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.2-3-gd478f380-rebuilt.opensuse.org 04/01/2014 Call Trace: dump_stack_lvl+0x4a/0x80 print_report+0xcf/0x650 ? srso_alias_return_thunk+0x5/0x7f ? srso_alias_return_thunk+0x5/0x7f ? __phys_addr+0x46/0x90 kasan_report+0xda/0x110 ? smb2_query_info_compound+0x423/0x6d0 [cifs] ? smb2_query_info_compound+0x423/0x6d0 [cifs] smb2_query_info_compound+0x423/0x6d0 [cifs] ? __pfx_smb2_query_info_compound+0x10/0x10 [cifs] ? srso_alias_return_thunk+0x5/0x7f ? __stack_depot_save+0x39/0x480 ? kasan_save_stack+0x33/0x60 ? kasan_set_track+0x25/0x30 ? ____kasan_slab_free+0x126/0x170 smb2_queryfs+0xc2/0x2c0 [cifs] ? __pfx_smb2_queryfs+0x10/0x10 [cifs] ? __pfx___lock_acquire+0x10/0x10 smb311_queryfs+0x210/0x220 [cifs] ? __pfx_smb311_queryfs+0x10/0x10 [cifs] ? srso_alias_return_thunk+0x5/0x7f ? __lock_acquire+0x480/0x26c0 ? lock_release+0x1ed/0x640 ? srso_alias_return_thunk+0x5/0x7f ? do_raw_spin_unlock+0x9b/0x100 cifs_statfs+0x18c/0x4b0 [cifs] statfs_by_dentry+0x9b/0xf0 fd_statfs+0x4e/0xb0 __do_sys_fstatfs+0x7f/0xe0 ? __pfx___do_sys_fstatfs+0x10/0x10 ? srso_alias_return_thunk+0x5/0x7f ? lockdep_hardirqs_on_prepare+0x136/0x200 ? srso_alias_return_thunk+0x5/0x7f do_syscall_64+0x3f/0x90 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 Allocated by task 27534: kasan_save_stack+0x33/0x60 kasan_set_track+0x25/0x30 __kasan_kmalloc+0x8f/0xa0 open_cached_dir+0x71b/0x1240 [cifs] smb2_query_info_compound+0x5c3/0x6d0 [cifs] smb2_queryfs+0xc2/0x2c0 [cifs] smb311_queryfs+0x210/0x220 [cifs] cifs_statfs+0x18c/0x4b0 [cifs] statfs_by_dentry+0x9b/0xf0 fd_statfs+0x4e/0xb0 __do_sys_fstatfs+0x7f/0xe0 do_syscall_64+0x3f/0x90 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 Freed by task 27534: kasan_save_stack+0x33/0x60 kasan_set_track+0x25/0x30 kasan_save_free_info+0x2b/0x50 ____kasan_slab_free+0x126/0x170 slab_free_freelist_hook+0xd0/0x1e0 __kmem_cache_free+0x9d/0x1b0 open_cached_dir+0xff5/0x1240 [cifs] smb2_query_info_compound+0x5c3/0x6d0 [cifs] smb2_queryfs+0xc2/0x2c0 [cifs] This is a race between open_cached_dir() and cached_dir_lease_break() where the cache entry for the open directory handle receives a lease break while creating it. And before returning from open_cached_dir(), we put the last reference of the new @cfid because of !@cfid->has_lease. Besides the UAF, while running xfstests a lot of missed lease breaks have been noticed in tests that run several concurrent statfs(2) calls on those cached fids CIFS: VFS: \\w22-root1.gandalf.test No task to wake, unknown frame... CIFS: VFS: \\w22-root1.gandalf.test Cmd: 18 Err: 0x0 Flags: 0x1... CIFS: VFS: \\w22-root1.gandalf.test smb buf 00000000715bfe83 len 108 CIFS: VFS: Dump pending requests: CIFS: VFS: \\w22-root1.gandalf.test No task to wake, unknown frame... CIFS: VFS: \\w22-root1.gandalf.test Cmd: 18 Err: 0x0 Flags: 0x1... CIFS: VFS: \\w22-root1.gandalf.test smb buf 000000005aa7316e len 108 ... To fix both, in open_cached_dir() ensure that @cfid->has_lease is set right before sending out compounded request so that any potential lease break will be get processed by demultiplex thread while we're still caching @cfid. And, if open failed for some reason, re-check @cfid->has_lease to decide whether or not put lease reference. Cc: stable@vger.kernel.org Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>

Fix kernel crash in AP bus code caused by very early invocation of the config change callback function via SCLP. After a fresh IML of the machine the crypto cards are still offline and will get switched online only with activation of any LPAR which has the card in it's configuration. A crypto card coming online is reported to the LPAR via SCLP and the AP bus offers a callback function to get this kind of information. However, it may happen that the callback is invoked before the AP bus init function is complete. As the callback triggers a synchronous AP bus scan, the scan may already run but some internal states are not initialized by the AP bus init function resulting in a crash like this: [ 11.635859] Unable to handle kernel pointer dereference in virtual kernel address space [ 11.635861] Failing address: 0000000000000000 TEID: 0000000000000887 [ 11.635862] Fault in home space mode while using kernel ASCE. [ 11.635864] AS:00000000894c4007 R3:00000001fece8007 S:00000001fece7800 P:000000000000013d [ 11.635879] Oops: 0004 ilc:1 [#1] SMP [ 11.635882] Modules linked in: [ 11.635884] CPU: 5 PID: 42 Comm: kworker/5:0 Not tainted 6.6.0-rc3-00003-g4dbf7cdc6b42 #12 [ 11.635886] Hardware name: IBM 3931 A01 751 (LPAR) [ 11.635887] Workqueue: events_long ap_scan_bus [ 11.635891] Krnl PSW : 0704c00180000000 0000000000000000 (0x0) [ 11.635895] R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 RI:0 EA:3 [ 11.635897] Krnl GPRS: 0000000001000a00 0000000000000000 0000000000000006 0000000089591940 [ 11.635899] 0000000080000000 0000000000000a00 0000000000000000 0000000000000000 [ 11.635901] 0000000081870c00 0000000089591000 000000008834e4e2 0000000002625a00 [ 11.635903] 0000000081734200 0000038000913c18 000000008834c6d6 0000038000913ac8 [ 11.635906] Krnl Code:>0000000000000000: 0000 illegal [ 11.635906] 0000000000000002: 0000 illegal [ 11.635906] 0000000000000004: 0000 illegal [ 11.635906] 0000000000000006: 0000 illegal [ 11.635906] 0000000000000008: 0000 illegal [ 11.635906] 000000000000000a: 0000 illegal [ 11.635906] 000000000000000c: 0000 illegal [ 11.635906] 000000000000000e: 0000 illegal [ 11.635915] Call Trace: [ 11.635916] [<0000000000000000>] 0x0 [ 11.635918] [<000000008834e4e2>] ap_queue_init_state+0x82/0xb8 [ 11.635921] [<000000008834ba1c>] ap_scan_domains+0x6fc/0x740 [ 11.635923] [<000000008834c092>] ap_scan_adapter+0x632/0x8b0 [ 11.635925] [<000000008834c3e4>] ap_scan_bus+0xd4/0x288 [ 11.635927] [<00000000879a33ba>] process_one_work+0x19a/0x410 [ 11.635930] Discipline DIAG cannot be used without z/VM [ 11.635930] [<00000000879a3a2c>] worker_thread+0x3fc/0x560 [ 11.635933] [<00000000879aea60>] kthread+0x120/0x128 [ 11.635936] [<000000008792afa4>] __ret_from_fork+0x3c/0x58 [ 11.635938] [<00000000885ebe62>] ret_from_fork+0xa/0x30 [ 11.635942] Last Breaking-Event-Address: [ 11.635942] [<000000008834c6d4>] ap_wait+0xcc/0x148 This patch improves the ap_bus_force_rescan() function which is invoked by the config change callback by checking if a first initial AP bus scan has been done. If not, the force rescan request is simple ignored. Anyhow it does not make sense to trigger AP bus re-scans even before the very first bus scan is complete. Cc: stable@vger.kernel.org Reviewed-by: Holger Dengler <dengler@linux.ibm.com> Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

The cloned child of ahash that uses shash under the hood should use shash helpers (like crypto_shash_setkey()). The following panic may be observed on TCP-AO selftests: > ================================================================== > BUG: KASAN: wild-memory-access in crypto_mod_get+0x1b/0x60 > Write of size 4 at addr 5d5be0ff5c415e14 by task connect_ipv4/1397 > > CPU: 0 PID: 1397 Comm: connect_ipv4 Tainted: G W 6.6.0+ #47 > Call Trace: > <TASK> > dump_stack_lvl+0x46/0x70 > kasan_report+0xc3/0xf0 > kasan_check_range+0xec/0x190 > crypto_mod_get+0x1b/0x60 > crypto_spawn_alg+0x53/0x140 > crypto_spawn_tfm2+0x13/0x60 > hmac_init_tfm+0x25/0x60 > crypto_ahash_setkey+0x8b/0x100 > tcp_ao_add_cmd+0xe7a/0x1120 > do_tcp_setsockopt+0x5ed/0x12a0 > do_sock_setsockopt+0x82/0x100 > __sys_setsockopt+0xe9/0x160 > __x64_sys_setsockopt+0x60/0x70 > do_syscall_64+0x3c/0xe0 > entry_SYSCALL_64_after_hwframe+0x46/0x4e > ================================================================== > general protection fault, probably for non-canonical address 0x5d5be0ff5c415e14: 0000 [#1] PREEMPT SMP KASAN > CPU: 0 PID: 1397 Comm: connect_ipv4 Tainted: G B W 6.6.0+ #47 > Call Trace: > <TASK> > ? die_addr+0x3c/0xa0 > ? exc_general_protection+0x144/0x210 > ? asm_exc_general_protection+0x22/0x30 > ? add_taint+0x26/0x90 > ? crypto_mod_get+0x20/0x60 > ? crypto_mod_get+0x1b/0x60 > ? ahash_def_finup_done1+0x58/0x80 > crypto_spawn_alg+0x53/0x140 > crypto_spawn_tfm2+0x13/0x60 > hmac_init_tfm+0x25/0x60 > crypto_ahash_setkey+0x8b/0x100 > tcp_ao_add_cmd+0xe7a/0x1120 > do_tcp_setsockopt+0x5ed/0x12a0 > do_sock_setsockopt+0x82/0x100 > __sys_setsockopt+0xe9/0x160 > __x64_sys_setsockopt+0x60/0x70 > do_syscall_64+0x3c/0xe0 > entry_SYSCALL_64_after_hwframe+0x46/0x4e > </TASK> > RIP: 0010:crypto_mod_get+0x20/0x60 Make sure that the child/clone has using_shash set when parent is an shash user. Fixes: 2f1f34c ("crypto: ahash - optimize performance when wrapping shash") Cc: David Ahern <dsahern@kernel.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Dmitry Safonov <0x7f454c46@gmail.com> Cc: Eric Biggers <ebiggers@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Francesco Ruggeri <fruggeri05@gmail.com> To: Herbert Xu <herbert@gondor.apana.org.au> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Paolo Abeni <pabeni@redhat.com> Cc: Salam Noureddine <noureddine@arista.com> Cc: netdev@vger.kernel.org Cc: linux-crypto@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Dmitry Safonov <dima@arista.com> Reviewed-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

…pf_iter_reg' Chuyi Zhou says: ==================== The patchset aims to let the BPF verivier consider bpf_iter__cgroup->cgroup and bpf_iter__task->task is trusted suggested by Alexei[1]. Please see individual patches for more details. And comments are always welcome. Link[1]:https://lore.kernel.org/bpf/20231022154527.229117-1-zhouchuyi@bytedance.com/T/#mb57725edc8ccdd50a1b165765c7619b4d65ed1b0 v2->v1: * Patch #1: Add Yonghong's ack and add description of similar case in log. * Patch #2: Add Yonghong's ack ==================== Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>

We must check the return value of find_first_bit() before using the return value as an index array since it happens to overflow the array and then panic: [ 107.318430] Kernel BUG [#1] [ 107.319434] CPU: 3 PID: 1238 Comm: kill Tainted: G E 6.6.0-rc6ubuntu-defconfig #2 [ 107.319465] Hardware name: riscv-virtio,qemu (DT) [ 107.319551] epc : pmu_sbi_ovf_handler+0x3a4/0x3ae [ 107.319840] ra : pmu_sbi_ovf_handler+0x52/0x3ae [ 107.319868] epc : ffffffff80a0a77c ra : ffffffff80a0a42a sp : ffffaf83fecda350 [ 107.319884] gp : ffffffff823961a8 tp : ffffaf8083db1dc0 t0 : ffffaf83fecda480 [ 107.319899] t1 : ffffffff80cafe62 t2 : 000000000000ff00 s0 : ffffaf83fecda520 [ 107.319921] s1 : ffffaf83fecda380 a0 : 00000018fca29df0 a1 : ffffffffffffffff [ 107.319936] a2 : 0000000001073734 a3 : 0000000000000004 a4 : 0000000000000000 [ 107.319951] a5 : 0000000000000040 a6 : 000000001d1c8774 a7 : 0000000000504d55 [ 107.319965] s2 : ffffffff82451f10 s3 : ffffffff82724e70 s4 : 000000000000003f [ 107.319980] s5 : 0000000000000011 s6 : ffffaf8083db27c0 s7 : 0000000000000000 [ 107.319995] s8 : 0000000000000001 s9 : 00007fffb45d6558 s10: 00007fffb45d81a0 [ 107.320009] s11: ffffaf7ffff60000 t3 : 0000000000000004 t4 : 0000000000000000 [ 107.320023] t5 : ffffaf7f80000000 t6 : ffffaf8000000000 [ 107.320037] status: 0000000200000100 badaddr: 0000000000000000 cause: 0000000000000003 [ 107.320081] [<ffffffff80a0a77c>] pmu_sbi_ovf_handler+0x3a4/0x3ae [ 107.320112] [<ffffffff800b42d0>] handle_percpu_devid_irq+0x9e/0x1a0 [ 107.320131] [<ffffffff800ad92c>] generic_handle_domain_irq+0x28/0x36 [ 107.320148] [<ffffffff8065f9f8>] riscv_intc_irq+0x36/0x4e [ 107.320166] [<ffffffff80caf4a0>] handle_riscv_irq+0x54/0x86 [ 107.320189] [<ffffffff80cb0036>] do_irq+0x64/0x96 [ 107.320271] Code: 85a6 855e b097 ff7f 80e7 9220 b709 9002 4501 bbd9 (9002) 6097 [ 107.320585] ---[ end trace 0000000000000000 ]--- [ 107.320704] Kernel panic - not syncing: Fatal exception in interrupt [ 107.320775] SMP: stopping secondary CPUs [ 107.321219] Kernel Offset: 0x0 from 0xffffffff80000000 [ 107.333051] ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]--- Fixes: 4905ec2 ("RISC-V: Add sscofpmf extension support") Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Link: https://lore.kernel.org/r/20231109082128.40777-1-alexghiti@rivosinc.com Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

====================================================== WARNING: possible circular locking dependency detected 6.5.0-kfd-fkuehlin #276 Not tainted ------------------------------------------------------ kworker/8:2/2676 is trying to acquire lock: ffff9435aae95c88 ((work_completion)(&svm_bo->eviction_work)){+.+.}-{0:0}, at: __flush_work+0x52/0x550 but task is already holding lock: ffff9435cd8e1720 (&svms->lock){+.+.}-{3:3}, at: svm_range_deferred_list_work+0xe8/0x340 [amdgpu] which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&svms->lock){+.+.}-{3:3}: __mutex_lock+0x97/0xd30 kfd_ioctl_alloc_memory_of_gpu+0x6d/0x3c0 [amdgpu] kfd_ioctl+0x1b2/0x5d0 [amdgpu] __x64_sys_ioctl+0x86/0xc0 do_syscall_64+0x39/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #1 (&mm->mmap_lock){++++}-{3:3}: down_read+0x42/0x160 svm_range_evict_svm_bo_worker+0x8b/0x340 [amdgpu] process_one_work+0x27a/0x540 worker_thread+0x53/0x3e0 kthread+0xeb/0x120 ret_from_fork+0x31/0x50 ret_from_fork_asm+0x11/0x20 -> #0 ((work_completion)(&svm_bo->eviction_work)){+.+.}-{0:0}: __lock_acquire+0x1426/0x2200 lock_acquire+0xc1/0x2b0 __flush_work+0x80/0x550 __cancel_work_timer+0x109/0x190 svm_range_bo_release+0xdc/0x1c0 [amdgpu] svm_range_free+0x175/0x180 [amdgpu] svm_range_deferred_list_work+0x15d/0x340 [amdgpu] process_one_work+0x27a/0x540 worker_thread+0x53/0x3e0 kthread+0xeb/0x120 ret_from_fork+0x31/0x50 ret_from_fork_asm+0x11/0x20 other info that might help us debug this: Chain exists of: (work_completion)(&svm_bo->eviction_work) --> &mm->mmap_lock --> &svms->lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&svms->lock); lock(&mm->mmap_lock); lock(&svms->lock); lock((work_completion)(&svm_bo->eviction_work)); I believe this cannot really lead to a deadlock in practice, because svm_range_evict_svm_bo_worker only takes the mmap_read_lock if the BO refcount is non-0. That means it's impossible that svm_range_bo_release is running concurrently. However, there is no good way to annotate this. To avoid the problem, take a BO reference in svm_range_schedule_evict_svm_bo instead of in the worker. That way it's impossible for a BO to get freed while eviction work is pending and the cancel_work_sync call in svm_range_bo_release can be eliminated. v2: Use svm_bo_ref_unless_zero and explained why that's safe. Also removed redundant checks that are already done in amdkfd_fence_enable_signaling. Signed-off-by: Felix Kuehling <felix.kuehling@amd.com> Reviewed-by: Philip Yang <philip.yang@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

====================================================== WARNING: possible circular locking dependency detected 6.5.0-kfd-yangp #2289 Not tainted ------------------------------------------------------ kworker/0:2/996 is trying to acquire lock: (srcu){.+.+}-{0:0}, at: __synchronize_srcu+0x5/0x1a0 but task is already holding lock: ((work_completion)(&svms->deferred_list_work)){+.+.}-{0:0}, at: process_one_work+0x211/0x560 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 ((work_completion)(&svms->deferred_list_work)){+.+.}-{0:0}: __flush_work+0x88/0x4f0 svm_range_list_lock_and_flush_work+0x3d/0x110 [amdgpu] svm_range_set_attr+0xd6/0x14c0 [amdgpu] kfd_ioctl+0x1d1/0x630 [amdgpu] __x64_sys_ioctl+0x88/0xc0 -> #2 (&info->lock#2){+.+.}-{3:3}: __mutex_lock+0x99/0xc70 amdgpu_amdkfd_gpuvm_restore_process_bos+0x54/0x740 [amdgpu] restore_process_helper+0x22/0x80 [amdgpu] restore_process_worker+0x2d/0xa0 [amdgpu] process_one_work+0x29b/0x560 worker_thread+0x3d/0x3d0 -> #1 ((work_completion)(&(&process->restore_work)->work)){+.+.}-{0:0}: __flush_work+0x88/0x4f0 __cancel_work_timer+0x12c/0x1c0 kfd_process_notifier_release_internal+0x37/0x1f0 [amdgpu] __mmu_notifier_release+0xad/0x240 exit_mmap+0x6a/0x3a0 mmput+0x6a/0x120 do_exit+0x322/0xb90 do_group_exit+0x37/0xa0 __x64_sys_exit_group+0x18/0x20 do_syscall_64+0x38/0x80 -> #0 (srcu){.+.+}-{0:0}: __lock_acquire+0x1521/0x2510 lock_sync+0x5f/0x90 __synchronize_srcu+0x4f/0x1a0 __mmu_notifier_release+0x128/0x240 exit_mmap+0x6a/0x3a0 mmput+0x6a/0x120 svm_range_deferred_list_work+0x19f/0x350 [amdgpu] process_one_work+0x29b/0x560 worker_thread+0x3d/0x3d0 other info that might help us debug this: Chain exists of: srcu --> &info->lock#2 --> (work_completion)(&svms->deferred_list_work) Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock((work_completion)(&svms->deferred_list_work)); lock(&info->lock#2); lock((work_completion)(&svms->deferred_list_work)); sync(srcu); Signed-off-by: Philip Yang <Philip.Yang@amd.com> Reviewed-by: Felix Kuehling <felix.kuehling@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

This reverts commit dad3fb67ca1cbef87ce700e83a55835e5921ce8a. The commit converted kernfs_idr_lock to an IRQ-safe raw_spinlock because it could be acquired while holding an rq lock through bpf_cgroup_from_id(). However, kernfs_idr_lock is held while doing GPF_NOWAIT allocations which involves acquiring an non-IRQ-safe and non-raw lock leading to the following lockdep warning: ============================= [ BUG: Invalid wait context ] 6.7.0-rc5-kzm9g-00251-g655022a45b1c #578 Not tainted ----------------------------- swapper/0/0 is trying to lock: dfbcd488 (&c->lock){....}-{3:3}, at: local_lock_acquire+0x0/0xa4 other info that might help us debug this: context-{5:5} 2 locks held by swapper/0/0: #0: dfbc9c60 (lock){+.+.}-{3:3}, at: local_lock_acquire+0x0/0xa4 #1: c0c012a8 (kernfs_idr_lock){....}-{2:2}, at: __kernfs_new_node.constprop.0+0x68/0x258 stack backtrace: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.7.0-rc5-kzm9g-00251-g655022a45b1c #578 Hardware name: Generic SH73A0 (Flattened Device Tree) unwind_backtrace from show_stack+0x10/0x14 show_stack from dump_stack_lvl+0x68/0x90 dump_stack_lvl from __lock_acquire+0x3cc/0x168c __lock_acquire from lock_acquire+0x274/0x30c lock_acquire from local_lock_acquire+0x28/0xa4 local_lock_acquire from ___slab_alloc+0x234/0x8a8 ___slab_alloc from __slab_alloc.constprop.0+0x30/0x44 __slab_alloc.constprop.0 from kmem_cache_alloc+0x7c/0x148 kmem_cache_alloc from radix_tree_node_alloc.constprop.0+0x44/0xdc radix_tree_node_alloc.constprop.0 from idr_get_free+0x110/0x2b8 idr_get_free from idr_alloc_u32+0x9c/0x108 idr_alloc_u32 from idr_alloc_cyclic+0x50/0xb8 idr_alloc_cyclic from __kernfs_new_node.constprop.0+0x88/0x258 __kernfs_new_node.constprop.0 from kernfs_create_root+0xbc/0x154 kernfs_create_root from sysfs_init+0x18/0x5c sysfs_init from mnt_init+0xc4/0x220 mnt_init from vfs_caches_init+0x6c/0x88 vfs_caches_init from start_kernel+0x474/0x528 start_kernel from 0x0 Let's rever the commit. It's undesirable to spread out raw spinlock usage anyway and the problem can be solved by protecting the lookup path with RCU instead. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Andrea Righi <andrea.righi@canonical.com> Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Link: http://lkml.kernel.org/r/CAMuHMdV=AKt+mwY7svEq5gFPx41LoSQZ_USME5_MEdWQze13ww@mail.gmail.com Link: https://lore.kernel.org/r/20240109214828.252092-2-tj@kernel.org Tested-by: Andrea Righi <andrea.righi@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

…n,npcm750-pwm-fan Commit 89fec12 ("hwmon: (npcm750-pwm-fan) Add NPCM8xx support") introduced support for PWM fans on Nuvoton's npcm845 SoC. This chip supports three PWM modules with four PWM channels each. The older npcm750 only supported two PWM modules. The commit did not take into account that the older SoC only supported two PWM modules. This results in a crash if npcm750 is instantiated when the code attempts to instantiate the non-existing third PWM module. Unable to handle kernel paging request at virtual address e0aa2000 when write [e0aa2000] *pgd=04ab6811, *pte=00000000, *ppte=00000000 Internal error: Oops: 807 [#1] SMP ARM Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Tainted: G N 6.7.0-next-20240112-dirty #3 Hardware name: NPCM7XX Chip family PC is at npcm7xx_pwm_fan_probe+0x204/0x890 LR is at arm_heavy_mb+0x1c/0x38 Fix the problem by detecting the number of supported PWM modules in the probe function and only instantiating the supported modules. Fixes: 89fec12 ("hwmon: (npcm750-pwm-fan) Add NPCM8xx support") Cc: Tomer Maimon <tmaimon77@gmail.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net>

…q_wake calls We found the following dmesg calltrace when testing the GMAC NIC notebook: [9.448656] ------------[ cut here ]------------ [9.448658] Unbalanced IRQ 43 wake disable [9.448673] WARNING: CPU: 3 PID: 1083 at kernel/irq/manage.c:688 irq_set_irq_wake+0xe0/0x128 [9.448717] CPU: 3 PID: 1083 Comm: ethtool Tainted: G O 4.19 #1 [9.448773] ... [9.448774] Call Trace: [9.448781] [<9000000000209b5c>] show_stack+0x34/0x140 [9.448788] [<9000000000d52700>] dump_stack+0x98/0xd0 [9.448794] [<9000000000228610>] __warn+0xa8/0x120 [9.448797] [<9000000000d2fb60>] report_bug+0x98/0x130 [9.448800] [<900000000020a418>] do_bp+0x248/0x2f0 [9.448805] [<90000000002035f4>] handle_bp_int+0x4c/0x78 [9.448808] [<900000000029ea40>] irq_set_irq_wake+0xe0/0x128 [9.448813] [<9000000000a96a7c>] stmmac_set_wol+0x134/0x150 [9.448819] [<9000000000be6ed0>] dev_ethtool+0x1368/0x2440 [9.448824] [<9000000000c08350>] dev_ioctl+0x1f8/0x3e0 [9.448827] [<9000000000bb2a34>] sock_ioctl+0x2a4/0x450 [9.448832] [<900000000046f044>] do_vfs_ioctl+0xa4/0x738 [9.448834] [<900000000046f778>] ksys_ioctl+0xa0/0xe8 [9.448837] [<900000000046f7d8>] sys_ioctl+0x18/0x28 [9.448840] [<9000000000211ab4>] syscall_common+0x20/0x34 [9.448842] ---[ end trace 40c18d9aec863c3e ]--- Multiple disable_irq_wake() calls will keep decreasing the IRQ wake_depth, When wake_depth is 0, calling disable_irq_wake() again, will report the above calltrace. Due to the need to appear in pairs, we cannot call disable_irq_wake() without calling enable_irq_wake(). Fix this by making sure there are no unbalanced disable_irq_wake() calls. Fixes: 3172d3a ("stmmac: support wake up irq from external sources (v3)") Signed-off-by: Qiang Ma <maqianga@uniontech.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://lore.kernel.org/r/20240112021249.24598-1-maqianga@uniontech.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Andrii Nakryiko says: ==================== Tighten up arg:ctx type enforcement Follow up fixes for kernel-side and libbpf-side logic around handling arg:ctx (__arg_ctx) tagged arguments of BPF global subprogs. Patch #1 adds libbpf feature detection of kernel-side __arg_ctx support to avoid unnecessary rewriting BTF types. With stricter kernel-side type enforcement this is now mandatory to avoid problems with using `struct bpf_user_pt_regs_t` instead of actual typedef. For __arg_ctx tagged arguments verifier is now supporting either `bpf_user_pt_regs_t` typedef or resolves it down to the actual struct (pt_regs/user_pt_regs/user_regs_struct), depending on architecture), but for old kernels without __arg_ctx support it's more backwards compatible for libbpf to use `struct bpf_user_pt_regs_t` rewrite which will work on wider range of kernels. So feature detection prevent libbpf accidentally breaking global subprogs on new kernels. We also adjust selftests to do similar feature detection (much simpler, but potentially breaking due to kernel source code refactoring, which is fine for selftests), and skip tests expecting libbpf's BTF type rewrites. Patch #2 is preparatory refactoring for patch #3 which adds type enforcement for arg:ctx tagged global subprog args. See the patch for specifics. Patch #4 adds many new cases to ensure type logic works as expected. Finally, patch #5 adds a relevant subset of kernel-side type checks to __arg_ctx cases that libbpf supports rewrite of. In libbpf's case, type violations are reported as warnings and BTF rewrite is not performed, which will eventually lead to BPF verifier complaining at program verification time. Good care was taken to avoid conflicts between bpf and bpf-next tree (which has few follow up refactorings in the same code area). Once trees converge some of the code will be moved around a bit (and some will be deleted), but with no change to functionality or general shape of the code. v2->v3: - support `bpf_user_pt_regs_t` typedef for KPROBE and PERF_EVENT (CI); v1->v2: - add user_pt_regs and user_regs_struct support for PERF_EVENT (CI); - drop FEAT_ARG_CTX_TAG enum leftover from patch #1; - fix warning about default: without break in the switch (CI). ==================== Link: https://lore.kernel.org/r/20240118033143.3384355-1-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Lately, a bug was found when many TC filters are added - at some point, several bugs are printed to dmesg [1] and the switch is crashed with segmentation fault. The issue starts when gen_pool_free() fails because of unexpected behavior - a try to free memory which is already freed, this leads to BUG() call which crashes the switch and makes many other bugs. Trying to track down the unexpected behavior led to a bug in eRP code. The function mlxsw_sp_acl_erp_table_alloc() gets a pointer to the allocated index, sets the value and returns an error code. When gen_pool_alloc() fails it returns address 0, we track it and return -ENOBUFS outside, BUT the call for gen_pool_alloc() already override the index in erp_table structure. This is a problem when such allocation is done as part of table expansion. This is not a new table, which will not be used in case of allocation failure. We try to expand eRP table and override the current index (non-zero) with zero. Then, it leads to an unexpected behavior when address 0 is freed twice. Note that address 0 is valid in erp_table->base_index and indeed other tables use it. gen_pool_alloc() fails in case that there is no space left in the pre-allocated pool, in our case, the pool is limited to ACL_MAX_ERPT_BANK_SIZE, which is read from hardware. When more than max erp entries are required, we exceed the limit and return an error, this error leads to "Failed to migrate vregion" print. Fix this by changing erp_table->base_index only in case of a successful allocation. Add a test case for such a scenario. Without this fix it causes segmentation fault: $ TESTS="max_erp_entries_test" ./tc_flower.sh ./tc_flower.sh: line 988: 1560 Segmentation fault tc filter del dev $h2 ingress chain $i protocol ip pref $i handle $j flower &>/dev/null [1]: kernel BUG at lib/genalloc.c:508! invalid opcode: 0000 [#1] PREEMPT SMP CPU: 6 PID: 3531 Comm: tc Not tainted 6.7.0-rc5-custom-ga6893f479f5e #1 Hardware name: Mellanox Technologies Ltd. MSN4700/VMOD0010, BIOS 5.11 07/12/2021 RIP: 0010:gen_pool_free_owner+0xc9/0xe0 ... Call Trace: <TASK> __mlxsw_sp_acl_erp_table_other_dec+0x70/0xa0 [mlxsw_spectrum] mlxsw_sp_acl_erp_mask_destroy+0xf5/0x110 [mlxsw_spectrum] objagg_obj_root_destroy+0x18/0x80 [objagg] objagg_obj_destroy+0x12c/0x130 [objagg] mlxsw_sp_acl_erp_mask_put+0x37/0x50 [mlxsw_spectrum] mlxsw_sp_acl_ctcam_region_entry_remove+0x74/0xa0 [mlxsw_spectrum] mlxsw_sp_acl_ctcam_entry_del+0x1e/0x40 [mlxsw_spectrum] mlxsw_sp_acl_tcam_ventry_del+0x78/0xd0 [mlxsw_spectrum] mlxsw_sp_flower_destroy+0x4d/0x70 [mlxsw_spectrum] mlxsw_sp_flow_block_cb+0x73/0xb0 [mlxsw_spectrum] tc_setup_cb_destroy+0xc1/0x180 fl_hw_destroy_filter+0x94/0xc0 [cls_flower] __fl_delete+0x1ac/0x1c0 [cls_flower] fl_destroy+0xc2/0x150 [cls_flower] tcf_proto_destroy+0x1a/0xa0 ... mlxsw_spectrum3 0000:07:00.0: Failed to migrate vregion mlxsw_spectrum3 0000:07:00.0: Failed to migrate vregion Fixes: f465261 ("mlxsw: spectrum_acl: Implement common eRP core") Signed-off-by: Amit Cohen <amcohen@nvidia.com> Signed-off-by: Ido Schimmel <idosch@nvidia.com> Signed-off-by: Petr Machata <petrm@nvidia.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Link: https://lore.kernel.org/r/4cfca254dfc0e5d283974801a24371c7b6db5989.1705502064.git.petrm@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Petr Machata says: ==================== mlxsw: Miscellaneous fixes This patchset is a bric-a-brac of fixes for bugs impacting mlxsw. - Patches #1 and #2 fix issues in ACL handling error paths. - Patch #3 fixes stack corruption in ACL code that a recent FW update has uncovered. - Patch #4 fixes an issue in handling of IPIP next hops. - Patch #5 fixes a typo in a the qos_pfc selftest - Patch #6 fixes the same selftest to work with 8-lane ports. ==================== Link: https://lore.kernel.org/r/cover.1705502064.git.petrm@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>

bch_fs::snapshots is allocated by kvzalloc in __snapshot_t_mut. It should be freed by kvfree not kfree. Or umount will triger: [ 406.829178 ] BUG: unable to handle page fault for address: ffffe7b487148008 [ 406.830676 ] #PF: supervisor read access in kernel mode [ 406.831643 ] #PF: error_code(0x0000) - not-present page [ 406.832487 ] PGD 0 P4D 0 [ 406.832898 ] Oops: 0000 [#1] PREEMPT SMP PTI [ 406.833512 ] CPU: 2 PID: 1754 Comm: umount Kdump: loaded Tainted: G OE 6.7.0-rc7-custom+ #90 [ 406.834746 ] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014 [ 406.835796 ] RIP: 0010:kfree+0x62/0x140 [ 406.836197 ] Code: 80 48 01 d8 0f 82 e9 00 00 00 48 c7 c2 00 00 00 80 48 2b 15 78 9f 1f 01 48 01 d0 48 c1 e8 0c 48 c1 e0 06 48 03 05 56 9f 1f 01 <48> 8b 50 08 48 89 c7 f6 c2 01 0f 85 b0 00 00 00 66 90 48 8b 07 f6 [ 406.837810 ] RSP: 0018:ffffb9d641607e48 EFLAGS: 00010286 [ 406.838213 ] RAX: ffffe7b487148000 RBX: ffffb9d645200000 RCX: ffffb9d641607dc4 [ 406.838738 ] RDX: 000065bb00000000 RSI: ffffffffc0d88b84 RDI: ffffb9d645200000 [ 406.839217 ] RBP: ffff9a4625d00068 R08: 0000000000000001 R09: 0000000000000001 [ 406.839650 ] R10: 0000000000000001 R11: 000000000000001f R12: ffff9a4625d4da80 [ 406.840055 ] R13: ffff9a4625d00000 R14: ffffffffc0e2eb20 R15: 0000000000000000 [ 406.840451 ] FS: 00007f0a264ffb80(0000) GS:ffff9a4e2d500000(0000) knlGS:0000000000000000 [ 406.840851 ] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 406.841125 ] CR2: ffffe7b487148008 CR3: 000000018c4d2000 CR4: 00000000000006f0 [ 406.841464 ] Call Trace: [ 406.841583 ] <TASK> [ 406.841682 ] ? __die+0x1f/0x70 [ 406.841828 ] ? page_fault_oops+0x159/0x470 [ 406.842014 ] ? fixup_exception+0x22/0x310 [ 406.842198 ] ? exc_page_fault+0x1ed/0x200 [ 406.842382 ] ? asm_exc_page_fault+0x22/0x30 [ 406.842574 ] ? bch2_fs_release+0x54/0x280 [bcachefs] [ 406.842842 ] ? kfree+0x62/0x140 [ 406.842988 ] ? kfree+0x104/0x140 [ 406.843138 ] bch2_fs_release+0x54/0x280 [bcachefs] [ 406.843390 ] kobject_put+0xb7/0x170 [ 406.843552 ] deactivate_locked_super+0x2f/0xa0 [ 406.843756 ] cleanup_mnt+0xba/0x150 [ 406.843917 ] task_work_run+0x59/0xa0 [ 406.844083 ] exit_to_user_mode_prepare+0x197/0x1a0 [ 406.844302 ] syscall_exit_to_user_mode+0x16/0x40 [ 406.844510 ] do_syscall_64+0x4e/0xf0 [ 406.844675 ] entry_SYSCALL_64_after_hwframe+0x6e/0x76 [ 406.844907 ] RIP: 0033:0x7f0a2664e4fb Signed-off-by: Su Yue <glass.su@suse.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

When I was testing mongodb over bcachefs with compression, there is a lockdep warning when snapshotting mongodb data volume. $ cat test.sh prog=bcachefs $prog subvolume create /mnt/data $prog subvolume create /mnt/data/snapshots while true;do $prog subvolume snapshot /mnt/data /mnt/data/snapshots/$(date +%s) sleep 1s done $ cat /etc/mongodb.conf systemLog: destination: file logAppend: true path: /mnt/data/mongod.log storage: dbPath: /mnt/data/ lockdep reports: [ 3437.452330] ====================================================== [ 3437.452750] WARNING: possible circular locking dependency detected [ 3437.453168] 6.7.0-rc7-custom+ #85 Tainted: G E [ 3437.453562] ------------------------------------------------------ [ 3437.453981] bcachefs/35533 is trying to acquire lock: [ 3437.454325] ffffa0a02b2b1418 (sb_writers#10){.+.+}-{0:0}, at: filename_create+0x62/0x190 [ 3437.454875] but task is already holding lock: [ 3437.455268] ffffa0a02b2b10e0 (&type->s_umount_key#48){.+.+}-{3:3}, at: bch2_fs_file_ioctl+0x232/0xc90 [bcachefs] [ 3437.456009] which lock already depends on the new lock. [ 3437.456553] the existing dependency chain (in reverse order) is: [ 3437.457054] -> #3 (&type->s_umount_key#48){.+.+}-{3:3}: [ 3437.457507] down_read+0x3e/0x170 [ 3437.457772] bch2_fs_file_ioctl+0x232/0xc90 [bcachefs] [ 3437.458206] __x64_sys_ioctl+0x93/0xd0 [ 3437.458498] do_syscall_64+0x42/0xf0 [ 3437.458779] entry_SYSCALL_64_after_hwframe+0x6e/0x76 [ 3437.459155] -> #2 (&c->snapshot_create_lock){++++}-{3:3}: [ 3437.459615] down_read+0x3e/0x170 [ 3437.459878] bch2_truncate+0x82/0x110 [bcachefs] [ 3437.460276] bchfs_truncate+0x254/0x3c0 [bcachefs] [ 3437.460686] notify_change+0x1f1/0x4a0 [ 3437.461283] do_truncate+0x7f/0xd0 [ 3437.461555] path_openat+0xa57/0xce0 [ 3437.461836] do_filp_open+0xb4/0x160 [ 3437.462116] do_sys_openat2+0x91/0xc0 [ 3437.462402] __x64_sys_openat+0x53/0xa0 [ 3437.462701] do_syscall_64+0x42/0xf0 [ 3437.462982] entry_SYSCALL_64_after_hwframe+0x6e/0x76 [ 3437.463359] -> #1 (&sb->s_type->i_mutex_key#15){+.+.}-{3:3}: [ 3437.463843] down_write+0x3b/0xc0 [ 3437.464223] bch2_write_iter+0x5b/0xcc0 [bcachefs] [ 3437.464493] vfs_write+0x21b/0x4c0 [ 3437.464653] ksys_write+0x69/0xf0 [ 3437.464839] do_syscall_64+0x42/0xf0 [ 3437.465009] entry_SYSCALL_64_after_hwframe+0x6e/0x76 [ 3437.465231] -> #0 (sb_writers#10){.+.+}-{0:0}: [ 3437.465471] __lock_acquire+0x1455/0x21b0 [ 3437.465656] lock_acquire+0xc6/0x2b0 [ 3437.465822] mnt_want_write+0x46/0x1a0 [ 3437.465996] filename_create+0x62/0x190 [ 3437.466175] user_path_create+0x2d/0x50 [ 3437.466352] bch2_fs_file_ioctl+0x2ec/0xc90 [bcachefs] [ 3437.466617] __x64_sys_ioctl+0x93/0xd0 [ 3437.466791] do_syscall_64+0x42/0xf0 [ 3437.466957] entry_SYSCALL_64_after_hwframe+0x6e/0x76 [ 3437.467180] other info that might help us debug this: [ 3437.469670] 2 locks held by bcachefs/35533: other info that might help us debug this: [ 3437.467507] Chain exists of: sb_writers#10 --> &c->snapshot_create_lock --> &type->s_umount_key#48 [ 3437.467979] Possible unsafe locking scenario: [ 3437.468223] CPU0 CPU1 [ 3437.468405] ---- ---- [ 3437.468585] rlock(&type->s_umount_key#48); [ 3437.468758] lock(&c->snapshot_create_lock); [ 3437.469030] lock(&type->s_umount_key#48); [ 3437.469291] rlock(sb_writers#10); [ 3437.469434] *** DEADLOCK *** [ 3437.469670] 2 locks held by bcachefs/35533: [ 3437.469838] #0: ffffa0a02ce00a88 (&c->snapshot_create_lock){++++}-{3:3}, at: bch2_fs_file_ioctl+0x1e3/0xc90 [bcachefs] [ 3437.470294] #1: ffffa0a02b2b10e0 (&type->s_umount_key#48){.+.+}-{3:3}, at: bch2_fs_file_ioctl+0x232/0xc90 [bcachefs] [ 3437.470744] stack backtrace: [ 3437.470922] CPU: 7 PID: 35533 Comm: bcachefs Kdump: loaded Tainted: G E 6.7.0-rc7-custom+ #85 [ 3437.471313] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014 [ 3437.471694] Call Trace: [ 3437.471795] <TASK> [ 3437.471884] dump_stack_lvl+0x57/0x90 [ 3437.472035] check_noncircular+0x132/0x150 [ 3437.472202] __lock_acquire+0x1455/0x21b0 [ 3437.472369] lock_acquire+0xc6/0x2b0 [ 3437.472518] ? filename_create+0x62/0x190 [ 3437.472683] ? lock_is_held_type+0x97/0x110 [ 3437.472856] mnt_want_write+0x46/0x1a0 [ 3437.473025] ? filename_create+0x62/0x190 [ 3437.473204] filename_create+0x62/0x190 [ 3437.473380] user_path_create+0x2d/0x50 [ 3437.473555] bch2_fs_file_ioctl+0x2ec/0xc90 [bcachefs] [ 3437.473819] ? lock_acquire+0xc6/0x2b0 [ 3437.474002] ? __fget_files+0x2a/0x190 [ 3437.474195] ? __fget_files+0xbc/0x190 [ 3437.474380] ? lock_release+0xc5/0x270 [ 3437.474567] ? __x64_sys_ioctl+0x93/0xd0 [ 3437.474764] ? __pfx_bch2_fs_file_ioctl+0x10/0x10 [bcachefs] [ 3437.475090] __x64_sys_ioctl+0x93/0xd0 [ 3437.475277] do_syscall_64+0x42/0xf0 [ 3437.475454] entry_SYSCALL_64_after_hwframe+0x6e/0x76 [ 3437.475691] RIP: 0033:0x7f2743c313af ====================================================== In __bch2_ioctl_subvolume_create(), we grab s_umount unconditionally and unlock it at the end of the function. There is a comment "why do we need this lock?" about the lock coming from commit 42d2373 ("bcachefs: Snapshot creation, deletion") The reason is that __bch2_ioctl_subvolume_create() calls sync_inodes_sb() which enforce locked s_umount to writeback all dirty nodes before doing snapshot works. Fix it by read locking s_umount for snapshotting only and unlocking s_umount after sync_inodes_sb(). Signed-off-by: Su Yue <glass.su@suse.com> Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

There is this reported crash when experimenting with the lvm2 testsuite. The list corruption is caused by the fact that the postsuspend and resume methods were not paired correctly; there were two consecutive calls to the origin_postsuspend function. The second call attempts to remove the "hash_list" entry from a list, while it was already removed by the first call. Fix __dm_internal_resume so that it calls the preresume and resume methods of the table's targets. If a preresume method of some target fails, we are in a tricky situation. We can't return an error because dm_internal_resume isn't supposed to return errors. We can't return success, because then the "resume" and "postsuspend" methods would not be paired correctly. So, we set the DMF_SUSPENDED flag and we fake normal suspend - it may confuse userspace tools, but it won't cause a kernel crash. ------------[ cut here ]------------ kernel BUG at lib/list_debug.c:56! invalid opcode: 0000 [#1] PREEMPT SMP CPU: 1 PID: 8343 Comm: dmsetup Not tainted 6.8.0-rc6 #4 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014 RIP: 0010:__list_del_entry_valid_or_report+0x77/0xc0 <snip> RSP: 0018:ffff8881b831bcc0 EFLAGS: 00010282 RAX: 000000000000004e RBX: ffff888143b6eb80 RCX: 0000000000000000 RDX: 0000000000000001 RSI: ffffffff819053d0 RDI: 00000000ffffffff RBP: ffff8881b83a3400 R08: 00000000fffeffff R09: 0000000000000058 R10: 0000000000000000 R11: ffffffff81a24080 R12: 0000000000000001 R13: ffff88814538e000 R14: ffff888143bc6dc0 R15: ffffffffa02e4bb0 FS: 00000000f7c0f780(0000) GS:ffff8893f0a40000(0000) knlGS:0000000000000000 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 0000000057fb5000 CR3: 0000000143474000 CR4: 00000000000006b0 Call Trace: <TASK> ? die+0x2d/0x80 ? do_trap+0xeb/0xf0 ? __list_del_entry_valid_or_report+0x77/0xc0 ? do_error_trap+0x60/0x80 ? __list_del_entry_valid_or_report+0x77/0xc0 ? exc_invalid_op+0x49/0x60 ? __list_del_entry_valid_or_report+0x77/0xc0 ? asm_exc_invalid_op+0x16/0x20 ? table_deps+0x1b0/0x1b0 [dm_mod] ? __list_del_entry_valid_or_report+0x77/0xc0 origin_postsuspend+0x1a/0x50 [dm_snapshot] dm_table_postsuspend_targets+0x34/0x50 [dm_mod] dm_suspend+0xd8/0xf0 [dm_mod] dev_suspend+0x1f2/0x2f0 [dm_mod] ? table_deps+0x1b0/0x1b0 [dm_mod] ctl_ioctl+0x300/0x5f0 [dm_mod] dm_compat_ctl_ioctl+0x7/0x10 [dm_mod] __x64_compat_sys_ioctl+0x104/0x170 do_syscall_64+0x184/0x1b0 entry_SYSCALL_64_after_hwframe+0x46/0x4e RIP: 0033:0xf7e6aead <snip> ---[ end trace 0000000000000000 ]--- Fixes: ffcc393 ("dm: enhance internal suspend and resume interface") Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>

Use rbi->len instead of rcd->len for non-dataring packet. Found issue: XDP_WARN: xdp_update_frame_from_buff(line:278): Driver BUG: missing reserved tailroom WARNING: CPU: 0 PID: 0 at net/core/xdp.c:586 xdp_warn+0xf/0x20 CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W O 6.5.1 #1 RIP: 0010:xdp_warn+0xf/0x20 ... ? xdp_warn+0xf/0x20 xdp_do_redirect+0x15f/0x1c0 vmxnet3_run_xdp+0x17a/0x400 [vmxnet3] vmxnet3_process_xdp+0xe4/0x760 [vmxnet3] ? vmxnet3_tq_tx_complete.isra.0+0x21e/0x2c0 [vmxnet3] vmxnet3_rq_rx_complete+0x7ad/0x1120 [vmxnet3] vmxnet3_poll_rx_only+0x2d/0xa0 [vmxnet3] __napi_poll+0x20/0x180 net_rx_action+0x177/0x390 Reported-by: Martin Zaharinov <micron10@gmail.com> Tested-by: Martin Zaharinov <micron10@gmail.com> Link: https://lore.kernel.org/netdev/74BF3CC8-2A3A-44FF-98C2-1E20F110A92E@gmail.com/ Fixes: 54f00cc ("vmxnet3: Add XDP support.") Signed-off-by: William Tu <witu@nvidia.com> Link: https://lore.kernel.org/r/20240309183147.28222-1-witu@nvidia.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Fix race condition leading to system crash during EEH error handling During EEH error recovery, the bnx2x driver's transmit timeout logic could cause a race condition when handling reset tasks. The bnx2x_tx_timeout() schedules reset tasks via bnx2x_sp_rtnl_task(), which ultimately leads to bnx2x_nic_unload(). In bnx2x_nic_unload() SGEs are freed using bnx2x_free_rx_sge_range(). However, this could overlap with the EEH driver's attempt to reset the device using bnx2x_io_slot_reset(), which also tries to free SGEs. This race condition can result in system crashes due to accessing freed memory locations in bnx2x_free_rx_sge() 799 static inline void bnx2x_free_rx_sge(struct bnx2x *bp, 800 struct bnx2x_fastpath *fp, u16 index) 801 { 802 struct sw_rx_page *sw_buf = &fp->rx_page_ring[index]; 803 struct page *page = sw_buf->page; .... where sw_buf was set to NULL after the call to dma_unmap_page() by the preceding thread. EEH: Beginning: 'slot_reset' PCI 0011:01:00.0#10000: EEH: Invoking bnx2x->slot_reset() bnx2x: [bnx2x_io_slot_reset:14228(eth1)]IO slot reset initializing... bnx2x 0011:01:00.0: enabling device (0140 -> 0142) bnx2x: [bnx2x_io_slot_reset:14244(eth1)]IO slot reset --> driver unload Kernel attempted to read user page (0) - exploit attempt? (uid: 0) BUG: Kernel NULL pointer dereference on read at 0x00000000 Faulting instruction address: 0xc0080000025065fc Oops: Kernel access of bad area, sig: 11 [#1] ..... Call Trace: [c000000003c67a20] [c00800000250658c] bnx2x_io_slot_reset+0x204/0x610 [bnx2x] (unreliable) [c000000003c67af0] [c0000000000518a8] eeh_report_reset+0xb8/0xf0 [c000000003c67b60] [c000000000052130] eeh_pe_report+0x180/0x550 [c000000003c67c70] [c00000000005318c] eeh_handle_normal_event+0x84c/0xa60 [c000000003c67d50] [c000000000053a84] eeh_event_handler+0xf4/0x170 [c000000003c67da0] [c000000000194c58] kthread+0x1c8/0x1d0 [c000000003c67e10] [c00000000000cf64] ret_from_kernel_thread+0x5c/0x64 To solve this issue, we need to verify page pool allocations before freeing. Fixes: 4cace67 ("bnx2x: Alloc 4k fragment for each rx ring buffer element") Signed-off-by: Thinh Tran <thinhtr@linux.ibm.com> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Link: https://lore.kernel.org/r/20240315205535.1321-1-thinhtr@linux.ibm.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>

The boot sequence evaluates CPUID information twice: 1) During early boot 2) When finalizing the early setup right before mitigations are selected and alternatives are patched. In both cases the evaluation is stored in boot_cpu_data, but on UP the copying of boot_cpu_data to the per CPU info of the boot CPU happens between #1 and #2. So any update which happens in #2 is never propagated to the per CPU info instance. Consolidate the whole logic and copy boot_cpu_data right before applying alternatives as that's the point where boot_cpu_data is in it's final state and not supposed to change anymore. This also removes the voodoo mb() from smp_prepare_cpus_common() which had absolutely no purpose. Fixes: 71eb489 ("x86/percpu: Cure per CPU madness on UP") Reported-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Tested-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20240322185305.127642785@linutronix.de

…rnel/git/netfilter/nf-next Pablo Neira Ayuso says: ==================== Netfilter updates for net-next The following patchset contains Netfilter updates for net-next: Patch #1 skips transaction if object type provides no .update interface. Patch #2 skips NETDEV_CHANGENAME which is unused. Patch #3 enables conntrack to handle Multicast Router Advertisements and Multicast Router Solicitations from the Multicast Router Discovery protocol (RFC4286) as untracked opposed to invalid packets. From Linus Luessing. Patch #4 updates DCCP conntracker to mark invalid as invalid, instead of dropping them, from Jason Xing. Patch #5 uses NF_DROP instead of -NF_DROP since NF_DROP is 0, also from Jason. Patch #6 removes reference in netfilter's sysctl documentation on pickup entries which were already removed by Florian Westphal. Patch #7 removes check for IPS_OFFLOAD flag to disable early drop which allows to evict entries from the conntrack table, also from Florian. Patches #8 to #16 updates nf_tables pipapo set backend to allocate the datastructure copy on-demand from preparation phase, to better deal with OOM situations where .commit step is too late to fail. Series from Florian Westphal. Patch #17 adds a selftest with packetdrill to cover conntrack TCP state transitions, also from Florian. Patch #18 use GFP_KERNEL to clone elements from control plane to avoid quick atomic reserves exhaustion with large sets, reporter refers to million entries magnitude. * tag 'nf-next-24-05-12' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next: netfilter: nf_tables: allow clone callbacks to sleep selftests: netfilter: add packetdrill based conntrack tests netfilter: nft_set_pipapo: remove dirty flag netfilter: nft_set_pipapo: move cloning of match info to insert/removal path netfilter: nft_set_pipapo: prepare pipapo_get helper for on-demand clone netfilter: nft_set_pipapo: merge deactivate helper into caller netfilter: nft_set_pipapo: prepare walk function for on-demand clone netfilter: nft_set_pipapo: prepare destroy function for on-demand clone netfilter: nft_set_pipapo: make pipapo_clone helper return NULL netfilter: nft_set_pipapo: move prove_locking helper around netfilter: conntrack: remove flowtable early-drop test netfilter: conntrack: documentation: remove reference to non-existent sysctl netfilter: use NF_DROP instead of -NF_DROP netfilter: conntrack: dccp: try not to drop skb in conntrack netfilter: conntrack: fix ct-state for ICMPv6 Multicast Router Discovery netfilter: nf_tables: remove NETDEV_CHANGENAME from netdev chain event handler netfilter: nf_tables: skip transaction if update object is not implemented ==================== Link: https://lore.kernel.org/r/20240512161436.168973-1-pablo@netfilter.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>

l2cap_le_flowctl_init() can cause both div-by-zero and an integer overflow since hdev->le_mtu may not fall in the valid range. Move MTU from hci_dev to hci_conn to validate MTU and stop the connection process earlier if MTU is invalid. Also, add a missing validation in read_buffer_size() and make it return an error value if the validation fails. Now hci_conn_add() returns ERR_PTR() as it can fail due to the both a kzalloc failure and invalid MTU value. divide error: 0000 [#1] PREEMPT SMP KASAN NOPTI CPU: 0 PID: 67 Comm: kworker/u5:0 Tainted: G W 6.9.0-rc5+ #20 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Workqueue: hci0 hci_rx_work RIP: 0010:l2cap_le_flowctl_init+0x19e/0x3f0 net/bluetooth/l2cap_core.c:547 Code: e8 17 17 0c 00 66 41 89 9f 84 00 00 00 bf 01 00 00 00 41 b8 02 00 00 00 4c 89 fe 4c 89 e2 89 d9 e8 27 17 0c 00 44 89 f0 31 d2 <66> f7 f3 89 c3 ff c3 4d 8d b7 88 00 00 00 4c 89 f0 48 c1 e8 03 42 RSP: 0018:ffff88810bc0f858 EFLAGS: 00010246 RAX: 00000000000002a0 RBX: 0000000000000000 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: ffff88810bc0f7c0 RDI: ffffc90002dcb66f RBP: ffff88810bc0f880 R08: aa69db2dda70ff01 R09: 0000ffaaaaaaaaaa R10: 0084000000ffaaaa R11: 0000000000000000 R12: ffff88810d65a084 R13: dffffc0000000000 R14: 00000000000002a0 R15: ffff88810d65a000 FS: 0000000000000000(0000) GS:ffff88811ac00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000100 CR3: 0000000103268003 CR4: 0000000000770ef0 PKRU: 55555554 Call Trace: <TASK> l2cap_le_connect_req net/bluetooth/l2cap_core.c:4902 [inline] l2cap_le_sig_cmd net/bluetooth/l2cap_core.c:5420 [inline] l2cap_le_sig_channel net/bluetooth/l2cap_core.c:5486 [inline] l2cap_recv_frame+0xe59d/0x11710 net/bluetooth/l2cap_core.c:6809 l2cap_recv_acldata+0x544/0x10a0 net/bluetooth/l2cap_core.c:7506 hci_acldata_packet net/bluetooth/hci_core.c:3939 [inline] hci_rx_work+0x5e5/0xb20 net/bluetooth/hci_core.c:4176 process_one_work kernel/workqueue.c:3254 [inline] process_scheduled_works+0x90f/0x1530 kernel/workqueue.c:3335 worker_thread+0x926/0xe70 kernel/workqueue.c:3416 kthread+0x2e3/0x380 kernel/kthread.c:388 ret_from_fork+0x5c/0x90 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK> Modules linked in: ---[ end trace 0000000000000000 ]--- Fixes: 6ed58ec ("Bluetooth: Use LE buffers for LE traffic") Suggested-by: Luiz Augusto von Dentz <luiz.dentz@gmail.com> Signed-off-by: Sungwoo Kim <iam@sung-woo.kim> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

Instead of printing three times the same output, print it only once, reducing lines and being sure that all no values have the same length. It also fixes an extra '\n' when running the with kernel threads, like here: =============== %< ============== Timer Latency 0 00:00:01 | IRQ Timer Latency (us) | Thread Timer Latency (us) CPU COUNT | cur min avg max | cur min avg max 2 #0 | - - - - | 161 161 161 161 3 #0 | - - - - | 161 161 161 161 8 #1 | 54 54 54 54 | - - - -'\n' ---------------|----------------------------------------|--------------------------------------- ALL #1 e0 | 54 54 54 | 161 161 161 =============== %< ============== This '\n' should have been removed with the user-space support that added another '\n' if not running with kernel threads. Link: https://lkml.kernel.org/r/0a4d8085e7cd706733a5dc10a81ca38b82bd4992.1713968967.git.bristot@kernel.org Cc: stable@vger.kernel.org Cc: Jonathan Corbet <corbet@lwn.net> Cc: Juri Lelli <juri.lelli@redhat.com> Fixes: cdca4f4 ("rtla/timerlat_top: Add timerlat user-space support") Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>

When running syzkaller with the newly reintroduced signed integer wrap sanitizer we encounter this splat: [ 366.015950] UBSAN: signed-integer-overflow in ../drivers/cdrom/cdrom.c:2361:33 [ 366.021089] -9223372036854775808 - 346321 cannot be represented in type '__s64' (aka 'long long') [ 366.025894] program syz-executor.4 is using a deprecated SCSI ioctl, please convert it to SG_IO [ 366.027502] CPU: 5 PID: 28472 Comm: syz-executor.7 Not tainted 6.8.0-rc2-00035-gb3ef86b5a957 #1 [ 366.027512] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 366.027518] Call Trace: [ 366.027523] <TASK> [ 366.027533] dump_stack_lvl+0x93/0xd0 [ 366.027899] handle_overflow+0x171/0x1b0 [ 366.038787] ata1.00: invalid multi_count 32 ignored [ 366.043924] cdrom_ioctl+0x2c3f/0x2d10 [ 366.063932] ? __pm_runtime_resume+0xe6/0x130 [ 366.071923] sr_block_ioctl+0x15d/0x1d0 [ 366.074624] ? __pfx_sr_block_ioctl+0x10/0x10 [ 366.077642] blkdev_ioctl+0x419/0x500 [ 366.080231] ? __pfx_blkdev_ioctl+0x10/0x10 ... Historically, the signed integer overflow sanitizer did not work in the kernel due to its interaction with `-fwrapv` but this has since been changed [1] in the newest version of Clang. It was re-enabled in the kernel with Commit 557f8c5 ("ubsan: Reintroduce signed overflow sanitizer"). Let's rearrange the check to not perform any arithmetic, thus not tripping the sanitizer. Link: llvm/llvm-project#82432 [1] Closes: KSPP/linux#354 Cc: linux-hardening@vger.kernel.org Signed-off-by: Justin Stitt <justinstitt@google.com> Link: https://lore.kernel.org/lkml/20240507-b4-sio-ata1-v1-1-810ffac6080a@google.com Reviewed-by: Phillip Potter <phil@philpotter.co.uk> Link: https://lore.kernel.org/lkml/ZjqU0fbzHrlnad8D@equinox Signed-off-by: Phillip Potter <phil@philpotter.co.uk> Link: https://lore.kernel.org/r/20240507222520.1445-2-phil@philpotter.co.uk Signed-off-by: Jens Axboe <axboe@kernel.dk>

A system crash like this Failing address: 200000cb7df6f000 TEID: 200000cb7df6f403 Fault in home space mode while using kernel ASCE. AS:00000002d71bc007 R3:00000003fe5b8007 S:000000011a446000 P:000000015660c13d Oops: 0038 ilc:3 [#1] PREEMPT SMP Modules linked in: mlx5_ib ... CPU: 8 PID: 7556 Comm: bash Not tainted 6.9.0-rc7 #8 Hardware name: IBM 3931 A01 704 (LPAR) Krnl PSW : 0704e00180000000 0000014b75e7b606 (ap_parse_bitmap_str+0x10e/0x1f8) R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:2 PM:0 RI:0 EA:3 Krnl GPRS: 0000000000000001 ffffffffffffffc0 0000000000000001 00000048f96b75d3 000000cb00000100 ffffffffffffffff ffffffffffffffff 000000cb7df6fce0 000000cb7df6fce0 00000000ffffffff 000000000000002b 00000048ffffffff 000003ff9b2dbc80 200000cb7df6fcd8 0000014bffffffc0 000000cb7df6fbc8 Krnl Code: 0000014b75e7b5fc: a7840047 brc 8,0000014b75e7b68a 0000014b75e7b600: 18b2 lr %r11,%r2 #0000014b75e7b602: a7f4000a brc 15,0000014b75e7b616 >0000014b75e7b606: eb22d00000e6 laog %r2,%r2,0(%r13) 0000014b75e7b60c: a7680001 lhi %r6,1 0000014b75e7b610: 187b lr %r7,%r11 0000014b75e7b612: 84960021 brxh %r9,%r6,0000014b75e7b654 0000014b75e7b616: 18e9 lr %r14,%r9 Call Trace: [<0000014b75e7b606>] ap_parse_bitmap_str+0x10e/0x1f8 ([<0000014b75e7b5dc>] ap_parse_bitmap_str+0xe4/0x1f8) [<0000014b75e7b758>] apmask_store+0x68/0x140 [<0000014b75679196>] kernfs_fop_write_iter+0x14e/0x1e8 [<0000014b75598524>] vfs_write+0x1b4/0x448 [<0000014b7559894c>] ksys_write+0x74/0x100 [<0000014b7618a440>] __do_syscall+0x268/0x328 [<0000014b761a3558>] system_call+0x70/0x98 INFO: lockdep is turned off. Last Breaking-Event-Address: [<0000014b75e7b636>] ap_parse_bitmap_str+0x13e/0x1f8 Kernel panic - not syncing: Fatal exception: panic_on_oops occured when /sys/bus/ap/a[pq]mask was updated with a relative mask value (like +0x10-0x12,+60,-90) with one of the numeric values exceeding INT_MAX. The fix is simple: use unsigned long values for the internal variables. The correct checks are already in place in the function but a simple int for the internal variables was used with the possibility to overflow. Reported-by: Marc Hartmayer <mhartmay@linux.ibm.com> Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Tested-by: Marc Hartmayer <mhartmay@linux.ibm.com> Reviewed-by: Holger Dengler <dengler@linux.ibm.com> Cc: <stable@vger.kernel.org> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

syzbot loves netrom, and found a possible deadlock in nr_rt_ioctl [1] Make sure we always acquire nr_node_list_lock before nr_node_lock(nr_node) [1] WARNING: possible circular locking dependency detected 6.9.0-rc7-syzkaller-02147-g654de42f3fc6 #0 Not tainted ------------------------------------------------------ syz-executor350/5129 is trying to acquire lock: ffff8880186e2070 (&nr_node->node_lock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff8880186e2070 (&nr_node->node_lock){+...}-{2:2}, at: nr_node_lock include/net/netrom.h:152 [inline] ffff8880186e2070 (&nr_node->node_lock){+...}-{2:2}, at: nr_dec_obs net/netrom/nr_route.c:464 [inline] ffff8880186e2070 (&nr_node->node_lock){+...}-{2:2}, at: nr_rt_ioctl+0x1bb/0x1090 net/netrom/nr_route.c:697 but task is already holding lock: ffffffff8f7053b8 (nr_node_list_lock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffffffff8f7053b8 (nr_node_list_lock){+...}-{2:2}, at: nr_dec_obs net/netrom/nr_route.c:462 [inline] ffffffff8f7053b8 (nr_node_list_lock){+...}-{2:2}, at: nr_rt_ioctl+0x10a/0x1090 net/netrom/nr_route.c:697 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (nr_node_list_lock){+...}-{2:2}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] nr_remove_node net/netrom/nr_route.c:299 [inline] nr_del_node+0x4b4/0x820 net/netrom/nr_route.c:355 nr_rt_ioctl+0xa95/0x1090 net/netrom/nr_route.c:683 sock_do_ioctl+0x158/0x460 net/socket.c:1222 sock_ioctl+0x629/0x8e0 net/socket.c:1341 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:904 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:890 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&nr_node->node_lock){+...}-{2:2}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain+0x18cb/0x58e0 kernel/locking/lockdep.c:3869 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] nr_node_lock include/net/netrom.h:152 [inline] nr_dec_obs net/netrom/nr_route.c:464 [inline] nr_rt_ioctl+0x1bb/0x1090 net/netrom/nr_route.c:697 sock_do_ioctl+0x158/0x460 net/socket.c:1222 sock_ioctl+0x629/0x8e0 net/socket.c:1341 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:904 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:890 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(nr_node_list_lock); lock(&nr_node->node_lock); lock(nr_node_list_lock); lock(&nr_node->node_lock); *** DEADLOCK *** 1 lock held by syz-executor350/5129: #0: ffffffff8f7053b8 (nr_node_list_lock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #0: ffffffff8f7053b8 (nr_node_list_lock){+...}-{2:2}, at: nr_dec_obs net/netrom/nr_route.c:462 [inline] #0: ffffffff8f7053b8 (nr_node_list_lock){+...}-{2:2}, at: nr_rt_ioctl+0x10a/0x1090 net/netrom/nr_route.c:697 stack backtrace: CPU: 0 PID: 5129 Comm: syz-executor350 Not tainted 6.9.0-rc7-syzkaller-02147-g654de42f3fc6 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2187 check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain+0x18cb/0x58e0 kernel/locking/lockdep.c:3869 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] nr_node_lock include/net/netrom.h:152 [inline] nr_dec_obs net/netrom/nr_route.c:464 [inline] nr_rt_ioctl+0x1bb/0x1090 net/netrom/nr_route.c:697 sock_do_ioctl+0x158/0x460 net/socket.c:1222 sock_ioctl+0x629/0x8e0 net/socket.c:1341 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:904 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:890 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Fixes: 1da177e ("Linux-2.6.12-rc2") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://lore.kernel.org/r/20240515142934.3708038-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Billy Jheng Bing-Jhong reported a race between __unix_gc() and queue_oob(). __unix_gc() tries to garbage-collect close()d inflight sockets, and then if the socket has MSG_OOB in unix_sk(sk)->oob_skb, GC will drop the reference and set NULL to it locklessly. However, the peer socket still can send MSG_OOB message and queue_oob() can update unix_sk(sk)->oob_skb concurrently, leading NULL pointer dereference. [0] To fix the issue, let's update unix_sk(sk)->oob_skb under the sk_receive_queue's lock and take it everywhere we touch oob_skb. Note that we defer kfree_skb() in manage_oob() to silence lockdep false-positive (See [1]). [0]: BUG: kernel NULL pointer dereference, address: 0000000000000008 PF: supervisor write access in kernel mode PF: error_code(0x0002) - not-present page PGD 8000000009f5e067 P4D 8000000009f5e067 PUD 9f5d067 PMD 0 Oops: 0002 [#1] PREEMPT SMP PTI CPU: 3 PID: 50 Comm: kworker/3:1 Not tainted 6.9.0-rc5-00191-gd091e579b864 #110 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 Workqueue: events delayed_fput RIP: 0010:skb_dequeue (./include/linux/skbuff.h:2386 ./include/linux/skbuff.h:2402 net/core/skbuff.c:3847) Code: 39 e3 74 3e 8b 43 10 48 89 ef 83 e8 01 89 43 10 49 8b 44 24 08 49 c7 44 24 08 00 00 00 00 49 8b 14 24 49 c7 04 24 00 00 00 00 <48> 89 42 08 48 89 10 e8 e7 c5 42 00 4c 89 e0 5b 5d 41 5c c3 cc cc RSP: 0018:ffffc900001bfd48 EFLAGS: 00000002 RAX: 0000000000000000 RBX: ffff8880088f5ae8 RCX: 00000000361289f9 RDX: 0000000000000000 RSI: 0000000000000206 RDI: ffff8880088f5b00 RBP: ffff8880088f5b00 R08: 0000000000080000 R09: 0000000000000001 R10: 0000000000000003 R11: 0000000000000001 R12: ffff8880056b6a00 R13: ffff8880088f5280 R14: 0000000000000001 R15: ffff8880088f5a80 FS: 0000000000000000(0000) GS:ffff88807dd80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000008 CR3: 0000000006314000 CR4: 00000000007506f0 PKRU: 55555554 Call Trace: <TASK> unix_release_sock (net/unix/af_unix.c:654) unix_release (net/unix/af_unix.c:1050) __sock_release (net/socket.c:660) sock_close (net/socket.c:1423) __fput (fs/file_table.c:423) delayed_fput (fs/file_table.c:444 (discriminator 3)) process_one_work (kernel/workqueue.c:3259) worker_thread (kernel/workqueue.c:3329 kernel/workqueue.c:3416) kthread (kernel/kthread.c:388) ret_from_fork (arch/x86/kernel/process.c:153) ret_from_fork_asm (arch/x86/entry/entry_64.S:257) </TASK> Modules linked in: CR2: 0000000000000008 Link: https://lore.kernel.org/netdev/a00d3993-c461-43f2-be6d-07259c98509a@rbox.co/ [1] Fixes: 1279f9d ("af_unix: Call kfree_skb() for dead unix_(sk)->oob_skb in GC.") Reported-by: Billy Jheng Bing-Jhong <billy@starlabs.sg> Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://lore.kernel.org/r/20240516134835.8332-1-kuniyu@amazon.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>

When CONFIG_DEBUG_BUGVERBOSE=n, we fail to add necessary padding bytes to bug_table entries, and as a result the last entry in a bug table will be ignored, potentially leading to an unexpected panic(). All prior entries in the table will be handled correctly. The arm64 ABI requires that struct fields of up to 8 bytes are naturally-aligned, with padding added within a struct such that struct are suitably aligned within arrays. When CONFIG_DEBUG_BUGVERPOSE=y, the layout of a bug_entry is: struct bug_entry { signed int bug_addr_disp; // 4 bytes signed int file_disp; // 4 bytes unsigned short line; // 2 bytes unsigned short flags; // 2 bytes } ... with 12 bytes total, requiring 4-byte alignment. When CONFIG_DEBUG_BUGVERBOSE=n, the layout of a bug_entry is: struct bug_entry { signed int bug_addr_disp; // 4 bytes unsigned short flags; // 2 bytes < implicit padding > // 2 bytes } ... with 8 bytes total, with 6 bytes of data and 2 bytes of trailing padding, requiring 4-byte alginment. When we create a bug_entry in assembly, we align the start of the entry to 4 bytes, which implicitly handles padding for any prior entries. However, we do not align the end of the entry, and so when CONFIG_DEBUG_BUGVERBOSE=n, the final entry lacks the trailing padding bytes. For the main kernel image this is not a problem as find_bug() doesn't depend on the trailing padding bytes when searching for entries: for (bug = __start___bug_table; bug < __stop___bug_table; ++bug) if (bugaddr == bug_addr(bug)) return bug; However for modules, module_bug_finalize() depends on the trailing bytes when calculating the number of entries: mod->num_bugs = sechdrs[i].sh_size / sizeof(struct bug_entry); ... and as the last bug_entry lacks the necessary padding bytes, this entry will not be counted, e.g. in the case of a single entry: sechdrs[i].sh_size == 6 sizeof(struct bug_entry) == 8; sechdrs[i].sh_size / sizeof(struct bug_entry) == 0; Consequently module_find_bug() will miss the last bug_entry when it does: for (i = 0; i < mod->num_bugs; ++i, ++bug) if (bugaddr == bug_addr(bug)) goto out; ... which can lead to a kenrel panic due to an unhandled bug. This can be demonstrated with the following module: static int __init buginit(void) { WARN(1, "hello\n"); return 0; } static void __exit bugexit(void) { } module_init(buginit); module_exit(bugexit); MODULE_LICENSE("GPL"); ... which will trigger a kernel panic when loaded: ------------[ cut here ]------------ hello Unexpected kernel BRK exception at EL1 Internal error: BRK handler: 00000000f2000800 [#1] PREEMPT SMP Modules linked in: hello(O+) CPU: 0 PID: 50 Comm: insmod Tainted: G O 6.9.1 #8 Hardware name: linux,dummy-virt (DT) pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : buginit+0x18/0x1000 [hello] lr : buginit+0x18/0x1000 [hello] sp : ffff800080533ae0 x29: ffff800080533ae0 x28: 0000000000000000 x27: 0000000000000000 x26: ffffaba8c4e70510 x25: ffff800080533c30 x24: ffffaba8c4a28a58 x23: 0000000000000000 x22: 0000000000000000 x21: ffff3947c0eab3c0 x20: ffffaba8c4e3f000 x19: ffffaba846464000 x18: 0000000000000006 x17: 0000000000000000 x16: ffffaba8c2492834 x15: 0720072007200720 x14: 0720072007200720 x13: ffffaba8c49b27c8 x12: 0000000000000312 x11: 0000000000000106 x10: ffffaba8c4a0a7c8 x9 : ffffaba8c49b27c8 x8 : 00000000ffffefff x7 : ffffaba8c4a0a7c8 x6 : 80000000fffff000 x5 : 0000000000000107 x4 : 0000000000000000 x3 : 0000000000000000 x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff3947c0eab3c0 Call trace: buginit+0x18/0x1000 [hello] do_one_initcall+0x80/0x1c8 do_init_module+0x60/0x218 load_module+0x1ba4/0x1d70 __do_sys_init_module+0x198/0x1d0 __arm64_sys_init_module+0x1c/0x28 invoke_syscall+0x48/0x114 el0_svc_common.constprop.0+0x40/0xe0 do_el0_svc+0x1c/0x28 el0_svc+0x34/0xd8 el0t_64_sync_handler+0x120/0x12c el0t_64_sync+0x190/0x194 Code: d0ffffe0 910003fd 91000000 9400000b (d4210000) ---[ end trace 0000000000000000 ]--- Kernel panic - not syncing: BRK handler: Fatal exception Fix this by always aligning the end of a bug_entry to 4 bytes, which is correct regardless of CONFIG_DEBUG_BUGVERBOSE. Fixes: 9fb7410 ("arm64/BUG: Use BRK instruction for generic BUG traps") Signed-off-by: Yuanbin Xie <xieyuanbin1@huawei.com> Signed-off-by: Jiangfeng Xiao <xiaojiangfeng@huawei.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/r/1716212077-43826-1-git-send-email-xiaojiangfeng@huawei.com Signed-off-by: Will Deacon <will@kernel.org>

…mit_queues' Writing 'power' and 'submit_queues' concurrently will trigger kernel panic: Test script: modprobe null_blk nr_devices=0 mkdir -p /sys/kernel/config/nullb/nullb0 while true; do echo 1 > submit_queues; echo 4 > submit_queues; done & while true; do echo 1 > power; echo 0 > power; done Test result: BUG: kernel NULL pointer dereference, address: 0000000000000148 Oops: 0000 [#1] PREEMPT SMP RIP: 0010:__lock_acquire+0x41d/0x28f0 Call Trace: <TASK> lock_acquire+0x121/0x450 down_write+0x5f/0x1d0 simple_recursive_removal+0x12f/0x5c0 blk_mq_debugfs_unregister_hctxs+0x7c/0x100 blk_mq_update_nr_hw_queues+0x4a3/0x720 nullb_update_nr_hw_queues+0x71/0xf0 [null_blk] nullb_device_submit_queues_store+0x79/0xf0 [null_blk] configfs_write_iter+0x119/0x1e0 vfs_write+0x326/0x730 ksys_write+0x74/0x150 This is because del_gendisk() can concurrent with blk_mq_update_nr_hw_queues(): nullb_device_power_store nullb_apply_submit_queues null_del_dev del_gendisk nullb_update_nr_hw_queues if (!dev->nullb) // still set while gendisk is deleted return 0 blk_mq_update_nr_hw_queues dev->nullb = NULL Fix this problem by resuing the global mutex to protect nullb_device_power_store() and nullb_update_nr_hw_queues() from configfs. Fixes: 45919fb ("null_blk: Enable modifying 'submit_queues' after an instance has been configured") Reported-and-tested-by: Yi Zhang <yi.zhang@redhat.com> Closes: https://lore.kernel.org/all/CAHj4cs9LgsHLnjg8z06LQ3Pr5cax-+Ps+xT7AP7TPnEjStuwZA@mail.gmail.com/ Signed-off-by: Yu Kuai <yukuai3@huawei.com> Reviewed-by: Zhu Yanjun <yanjun.zhu@linux.dev> Link: https://lore.kernel.org/r/20240523153934.1937851-1-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>

When I did memory failure tests recently, below panic occurs: kernel BUG at include/linux/mm.h:1135! invalid opcode: 0000 [#1] PREEMPT SMP NOPTI CPU: 9 PID: 137 Comm: kswapd1 Not tainted 6.9.0-rc4-00491-gd5ce28f156fe-dirty #14 RIP: 0010:shrink_huge_zero_page_scan+0x168/0x1a0 RSP: 0018:ffff9933c6c57bd0 EFLAGS: 00000246 RAX: 000000000000003e RBX: 0000000000000000 RCX: ffff88f61fc5c9c8 RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff88f61fc5c9c0 RBP: ffffcd7c446b0000 R08: ffffffff9a9405f0 R09: 0000000000005492 R10: 00000000000030ea R11: ffffffff9a9405f0 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: ffff88e703c4ac00 FS: 0000000000000000(0000) GS:ffff88f61fc40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055f4da6e9878 CR3: 0000000c71048000 CR4: 00000000000006f0 Call Trace: <TASK> do_shrink_slab+0x14f/0x6a0 shrink_slab+0xca/0x8c0 shrink_node+0x2d0/0x7d0 balance_pgdat+0x33a/0x720 kswapd+0x1f3/0x410 kthread+0xd5/0x100 ret_from_fork+0x2f/0x50 ret_from_fork_asm+0x1a/0x30 </TASK> Modules linked in: mce_inject hwpoison_inject ---[ end trace 0000000000000000 ]--- RIP: 0010:shrink_huge_zero_page_scan+0x168/0x1a0 RSP: 0018:ffff9933c6c57bd0 EFLAGS: 00000246 RAX: 000000000000003e RBX: 0000000000000000 RCX: ffff88f61fc5c9c8 RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff88f61fc5c9c0 RBP: ffffcd7c446b0000 R08: ffffffff9a9405f0 R09: 0000000000005492 R10: 00000000000030ea R11: ffffffff9a9405f0 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: ffff88e703c4ac00 FS: 0000000000000000(0000) GS:ffff88f61fc40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055f4da6e9878 CR3: 0000000c71048000 CR4: 00000000000006f0 The root cause is that HWPoison flag will be set for huge_zero_folio without increasing the folio refcnt. But then unpoison_memory() will decrease the folio refcnt unexpectedly as it appears like a successfully hwpoisoned folio leading to VM_BUG_ON_PAGE(page_ref_count(page) == 0) when releasing huge_zero_folio. Skip unpoisoning huge_zero_folio in unpoison_memory() to fix this issue. We're not prepared to unpoison huge_zero_folio yet. Link: https://lkml.kernel.org/r/20240516122608.22610-1-linmiaohe@huawei.com Fixes: 478d134 ("mm/huge_memory: do not overkill when splitting huge_zero_page") Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Yang Shi <shy828301@gmail.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Xu Yu <xuyu@linux.alibaba.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

…uddy pages When I did memory failure tests recently, below panic occurs: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x8cee00 flags: 0x6fffe0000000000(node=1|zone=2|lastcpupid=0x7fff) raw: 06fffe0000000000 dead000000000100 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000000009 00000000ffffffff 0000000000000000 page dumped because: VM_BUG_ON_PAGE(!PageBuddy(page)) ------------[ cut here ]------------ kernel BUG at include/linux/page-flags.h:1009! invalid opcode: 0000 [#1] PREEMPT SMP NOPTI RIP: 0010:__del_page_from_free_list+0x151/0x180 RSP: 0018:ffffa49c90437998 EFLAGS: 00000046 RAX: 0000000000000035 RBX: 0000000000000009 RCX: ffff8dd8dfd1c9c8 RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff8dd8dfd1c9c0 RBP: ffffd901233b8000 R08: ffffffffab5511f8 R09: 0000000000008c69 R10: 0000000000003c15 R11: ffffffffab5511f8 R12: ffff8dd8fffc0c80 R13: 0000000000000001 R14: ffff8dd8fffc0c80 R15: 0000000000000009 FS: 00007ff916304740(0000) GS:ffff8dd8dfd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055eae50124c8 CR3: 00000008479e0000 CR4: 00000000000006f0 Call Trace: <TASK> __rmqueue_pcplist+0x23b/0x520 get_page_from_freelist+0x26b/0xe40 __alloc_pages_noprof+0x113/0x1120 __folio_alloc_noprof+0x11/0xb0 alloc_buddy_hugetlb_folio.isra.0+0x5a/0x130 __alloc_fresh_hugetlb_folio+0xe7/0x140 alloc_pool_huge_folio+0x68/0x100 set_max_huge_pages+0x13d/0x340 hugetlb_sysctl_handler_common+0xe8/0x110 proc_sys_call_handler+0x194/0x280 vfs_write+0x387/0x550 ksys_write+0x64/0xe0 do_syscall_64+0xc2/0x1d0 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff916114887 RSP: 002b:00007ffec8a2fd78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000055eae500e350 RCX: 00007ff916114887 RDX: 0000000000000004 RSI: 000055eae500e390 RDI: 0000000000000003 RBP: 000055eae50104c0 R08: 0000000000000000 R09: 000055eae50104c0 R10: 0000000000000077 R11: 0000000000000246 R12: 0000000000000004 R13: 0000000000000004 R14: 00007ff916216b80 R15: 00007ff916216a00 </TASK> Modules linked in: mce_inject hwpoison_inject ---[ end trace 0000000000000000 ]--- And before the panic, there had an warning about bad page state: BUG: Bad page state in process page-types pfn:8cee00 page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x8cee00 flags: 0x6fffe0000000000(node=1|zone=2|lastcpupid=0x7fff) page_type: 0xffffff7f(buddy) raw: 06fffe0000000000 ffffd901241c0008 ffffd901240f8008 0000000000000000 raw: 0000000000000000 0000000000000009 00000000ffffff7f 0000000000000000 page dumped because: nonzero mapcount Modules linked in: mce_inject hwpoison_inject CPU: 8 PID: 154211 Comm: page-types Not tainted 6.9.0-rc4-00499-g5544ec3178e2-dirty #22 Call Trace: <TASK> dump_stack_lvl+0x83/0xa0 bad_page+0x63/0xf0 free_unref_page+0x36e/0x5c0 unpoison_memory+0x50b/0x630 simple_attr_write_xsigned.constprop.0.isra.0+0xb3/0x110 debugfs_attr_write+0x42/0x60 full_proxy_write+0x5b/0x80 vfs_write+0xcd/0x550 ksys_write+0x64/0xe0 do_syscall_64+0xc2/0x1d0 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f189a514887 RSP: 002b:00007ffdcd899718 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f189a514887 RDX: 0000000000000009 RSI: 00007ffdcd899730 RDI: 0000000000000003 RBP: 00007ffdcd8997a0 R08: 0000000000000000 R09: 00007ffdcd8994b2 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffdcda199a8 R13: 0000000000404af1 R14: 000000000040ad78 R15: 00007f189a7a5040 </TASK> The root cause should be the below race: memory_failure try_memory_failure_hugetlb me_huge_page __page_handle_poison dissolve_free_hugetlb_folio drain_all_pages -- Buddy page can be isolated e.g. for compaction. take_page_off_buddy -- Failed as page is not in the buddy list. -- Page can be putback into buddy after compaction. page_ref_inc -- Leads to buddy page with refcnt = 1. Then unpoison_memory() can unpoison the page and send the buddy page back into buddy list again leading to the above bad page state warning. And bad_page() will call page_mapcount_reset() to remove PageBuddy from buddy page leading to later VM_BUG_ON_PAGE(!PageBuddy(page)) when trying to allocate this page. Fix this issue by only treating __page_handle_poison() as successful when it returns 1. Link: https://lkml.kernel.org/r/20240523071217.1696196-1-linmiaohe@huawei.com Fixes: ceaf8fb ("mm, hwpoison: skip raw hwpoison page in freeing 1GB hugepage") Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

pcmoore added the enhancement label Feb 26, 2016

pcmoore added the priority/medium label Jun 1, 2016

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

RFE: audit device attach/detach events #1

RFE: audit device attach/detach events #1

pcmoore commented Feb 26, 2016

The-Mule commented Feb 16, 2017

pcmoore commented Feb 17, 2017

pcmoore commented Feb 17, 2017

RFE: audit device attach/detach events #1

RFE: audit device attach/detach events #1

Comments

pcmoore commented Feb 26, 2016

The-Mule commented Feb 16, 2017

pcmoore commented Feb 17, 2017

pcmoore commented Feb 17, 2017