[Question] RK3288 (Tinkerboard) maximum ethernet MTU #88

rfrht · 2018-04-22T22:43:28Z

I am re-posting this question, as issue #85 was closed by some Rockchip rep with no reply.

Hi there Rockchip / Maintainers;

What is the maximum supported MTU for RK3288 Gigabit Ethernet interface?

Trying to change MTU results a error here [using 4.4.120-beleza8-rockchip (Beleza8 is my build) from Armbian]:

root@tinkerboard:~# ifconfig eth0 mtu 8000
SIOCSIFMTU: Device or resource busy

Thanks a lot,

RF.

The text was updated successfully, but these errors were encountered:

When vb2_buffer_done is called the buffer is unbound from the request and put. The media_request_object_put also 'put's the request reference. If the application has already closed the request fd, then that means that the request reference at that point goes to 0 and the whole request is released. This means that the control handler associated with the request is also freed and that causes this kernel oops: [174705.995401] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:908 [174705.995411] in_atomic(): 1, irqs_disabled(): 1, pid: 28071, name: vivid-000-vid-o [174705.995416] 2 locks held by vivid-000-vid-o/28071: [174705.995420] #0: 000000001ea3a232 (&dev->mutex#3){....}, at: vivid_thread_vid_out+0x3f5/0x550 [vivid] [174705.995447] #1: 00000000e30a0d1e (&(&q->done_lock)->rlock){....}, at: vb2_buffer_done+0x92/0x1d0 [videobuf2_common] [174705.995460] Preemption disabled at: [174705.995461] [<0000000000000000>] (null) [174705.995472] CPU: 11 PID: 28071 Comm: vivid-000-vid-o Tainted: G W 4.20.0-rc1-test-no rockchip-linux#88 [174705.995476] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 05/19/2017 [174705.995481] Call Trace: [174705.995500] dump_stack+0x46/0x60 [174705.995512] ___might_sleep.cold.79+0xe1/0xf1 [174705.995523] __mutex_lock+0x50/0x8f0 [174705.995531] ? find_held_lock+0x2d/0x90 [174705.995536] ? find_held_lock+0x2d/0x90 [174705.995542] ? find_held_lock+0x2d/0x90 [174705.995564] ? v4l2_ctrl_handler_free.part.13+0x44/0x1d0 [videodev] [174705.995576] v4l2_ctrl_handler_free.part.13+0x44/0x1d0 [videodev] [174705.995590] v4l2_ctrl_request_release+0x1c/0x30 [videodev] [174705.995600] media_request_clean+0x64/0xe0 [media] [174705.995609] media_request_release+0x19/0x40 [media] [174705.995617] vb2_buffer_done+0xef/0x1d0 [videobuf2_common] [174705.995630] vivid_thread_vid_out+0x2c1/0x550 [vivid] [174705.995645] ? vivid_stop_generating_vid_cap+0x1c0/0x1c0 [vivid] [174705.995653] kthread+0x113/0x130 [174705.995659] ? kthread_park+0x80/0x80 [174705.995667] ret_from_fork+0x35/0x40 The vb2_buffer_done function can be called from interrupt context, so anything that sleeps is not allowed. The solution is to increment the request refcount when the buffer is queued and decrement it when the buffer is dequeued. Releasing the request is fine if that happens from VIDIOC_DQBUF. Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com> Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

syzbot was able to trigger another soft lockup [1] I first thought it was the O(N^2) issue I mentioned in my prior fix (f657d22ee1f "net/x25: do not hold the cpu too long in x25_new_lci()"), but I eventually found that x25_bind() was not checking SOCK_ZAPPED state under socket lock protection. This means that multiple threads can end up calling x25_insert_socket() for the same socket, and corrupt x25_list [1] watchdog: BUG: soft lockup - CPU#0 stuck for 123s! [syz-executor.2:10492] Modules linked in: irq event stamp: 27515 hardirqs last enabled at (27514): [<ffffffff81006673>] trace_hardirqs_on_thunk+0x1a/0x1c hardirqs last disabled at (27515): [<ffffffff8100668f>] trace_hardirqs_off_thunk+0x1a/0x1c softirqs last enabled at (32): [<ffffffff8632ee73>] x25_get_neigh+0xa3/0xd0 net/x25/x25_link.c:336 softirqs last disabled at (34): [<ffffffff86324bc3>] x25_find_socket+0x23/0x140 net/x25/af_x25.c:341 CPU: 0 PID: 10492 Comm: syz-executor.2 Not tainted 5.0.0-rc7+ rockchip-linux#88 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__sanitizer_cov_trace_pc+0x4/0x50 kernel/kcov.c:97 Code: f4 ff ff ff e8 11 9f ea ff 48 c7 05 12 fb e5 08 00 00 00 00 e9 c8 e9 ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 55 48 89 e5 <48> 8b 75 08 65 48 8b 04 25 40 ee 01 00 65 8b 15 38 0c 92 7e 81 e2 RSP: 0018:ffff88806e94fc48 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: 1ffff1100d84dac5 RBX: 0000000000000001 RCX: ffffc90006197000 RDX: 0000000000040000 RSI: ffffffff86324bf3 RDI: ffff88806c26d628 RBP: ffff88806e94fc48 R08: ffff88806c1c6500 R09: fffffbfff1282561 R10: fffffbfff1282560 R11: ffffffff89412b03 R12: ffff88806c26d628 R13: ffff888090455200 R14: dffffc0000000000 R15: 0000000000000000 FS: 00007f3a107e4700(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3a107e3db8 CR3: 00000000a5544000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __x25_find_socket net/x25/af_x25.c:327 [inline] x25_find_socket+0x7d/0x140 net/x25/af_x25.c:342 x25_new_lci net/x25/af_x25.c:355 [inline] x25_connect+0x380/0xde0 net/x25/af_x25.c:784 __sys_connect+0x266/0x330 net/socket.c:1662 __do_sys_connect net/socket.c:1673 [inline] __se_sys_connect net/socket.c:1670 [inline] __x64_sys_connect+0x73/0xb0 net/socket.c:1670 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457e29 Code: ad b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f3a107e3c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002a RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457e29 RDX: 0000000000000012 RSI: 0000000020000200 RDI: 0000000000000005 RBP: 000000000073c040 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f3a107e46d4 R13: 00000000004be362 R14: 00000000004ceb98 R15: 00000000ffffffff Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 10493 Comm: syz-executor.3 Not tainted 5.0.0-rc7+ rockchip-linux#88 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__read_once_size include/linux/compiler.h:193 [inline] RIP: 0010:queued_write_lock_slowpath+0x143/0x290 kernel/locking/qrwlock.c:86 Code: 4c 8d 2c 01 41 83 c7 03 41 0f b6 45 00 41 38 c7 7c 08 84 c0 0f 85 0c 01 00 00 8b 03 3d 00 01 00 00 74 1a f3 90 41 0f b6 55 00 <41> 38 d7 7c eb 84 d2 74 e7 48 89 df e8 cc aa 4e 00 eb dd be 04 00 RSP: 0018:ffff888085c47bd8 EFLAGS: 00000206 RAX: 0000000000000300 RBX: ffffffff89412b00 RCX: 1ffffffff1282560 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff89412b00 RBP: ffff888085c47c70 R08: 1ffffffff1282560 R09: fffffbfff1282561 R10: fffffbfff1282560 R11: ffffffff89412b03 R12: 00000000000000ff R13: fffffbfff1282560 R14: 1ffff11010b88f7d R15: 0000000000000003 FS: 00007fdd04086700(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fdd04064db8 CR3: 0000000090be0000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: queued_write_lock include/asm-generic/qrwlock.h:104 [inline] do_raw_write_lock+0x1d6/0x290 kernel/locking/spinlock_debug.c:203 __raw_write_lock_bh include/linux/rwlock_api_smp.h:204 [inline] _raw_write_lock_bh+0x3b/0x50 kernel/locking/spinlock.c:312 x25_insert_socket+0x21/0xe0 net/x25/af_x25.c:267 x25_bind+0x273/0x340 net/x25/af_x25.c:703 __sys_bind+0x23f/0x290 net/socket.c:1481 __do_sys_bind net/socket.c:1492 [inline] __se_sys_bind net/socket.c:1490 [inline] __x64_sys_bind+0x73/0xb0 net/socket.c:1490 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457e29 Fixes: 90c2729 ("X.25 remove bkl in bind") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: andrew hendry <andrew.hendry@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>

[ Upstream commit 797a22b ] syzbot was able to trigger another soft lockup [1] I first thought it was the O(N^2) issue I mentioned in my prior fix (f657d22ee1f "net/x25: do not hold the cpu too long in x25_new_lci()"), but I eventually found that x25_bind() was not checking SOCK_ZAPPED state under socket lock protection. This means that multiple threads can end up calling x25_insert_socket() for the same socket, and corrupt x25_list [1] watchdog: BUG: soft lockup - CPU#0 stuck for 123s! [syz-executor.2:10492] Modules linked in: irq event stamp: 27515 hardirqs last enabled at (27514): [<ffffffff81006673>] trace_hardirqs_on_thunk+0x1a/0x1c hardirqs last disabled at (27515): [<ffffffff8100668f>] trace_hardirqs_off_thunk+0x1a/0x1c softirqs last enabled at (32): [<ffffffff8632ee73>] x25_get_neigh+0xa3/0xd0 net/x25/x25_link.c:336 softirqs last disabled at (34): [<ffffffff86324bc3>] x25_find_socket+0x23/0x140 net/x25/af_x25.c:341 CPU: 0 PID: 10492 Comm: syz-executor.2 Not tainted 5.0.0-rc7+ #88 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__sanitizer_cov_trace_pc+0x4/0x50 kernel/kcov.c:97 Code: f4 ff ff ff e8 11 9f ea ff 48 c7 05 12 fb e5 08 00 00 00 00 e9 c8 e9 ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 55 48 89 e5 <48> 8b 75 08 65 48 8b 04 25 40 ee 01 00 65 8b 15 38 0c 92 7e 81 e2 RSP: 0018:ffff88806e94fc48 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: 1ffff1100d84dac5 RBX: 0000000000000001 RCX: ffffc90006197000 RDX: 0000000000040000 RSI: ffffffff86324bf3 RDI: ffff88806c26d628 RBP: ffff88806e94fc48 R08: ffff88806c1c6500 R09: fffffbfff1282561 R10: fffffbfff1282560 R11: ffffffff89412b03 R12: ffff88806c26d628 R13: ffff888090455200 R14: dffffc0000000000 R15: 0000000000000000 FS: 00007f3a107e4700(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3a107e3db8 CR3: 00000000a5544000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __x25_find_socket net/x25/af_x25.c:327 [inline] x25_find_socket+0x7d/0x140 net/x25/af_x25.c:342 x25_new_lci net/x25/af_x25.c:355 [inline] x25_connect+0x380/0xde0 net/x25/af_x25.c:784 __sys_connect+0x266/0x330 net/socket.c:1662 __do_sys_connect net/socket.c:1673 [inline] __se_sys_connect net/socket.c:1670 [inline] __x64_sys_connect+0x73/0xb0 net/socket.c:1670 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457e29 Code: ad b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f3a107e3c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002a RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457e29 RDX: 0000000000000012 RSI: 0000000020000200 RDI: 0000000000000005 RBP: 000000000073c040 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f3a107e46d4 R13: 00000000004be362 R14: 00000000004ceb98 R15: 00000000ffffffff Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 10493 Comm: syz-executor.3 Not tainted 5.0.0-rc7+ #88 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__read_once_size include/linux/compiler.h:193 [inline] RIP: 0010:queued_write_lock_slowpath+0x143/0x290 kernel/locking/qrwlock.c:86 Code: 4c 8d 2c 01 41 83 c7 03 41 0f b6 45 00 41 38 c7 7c 08 84 c0 0f 85 0c 01 00 00 8b 03 3d 00 01 00 00 74 1a f3 90 41 0f b6 55 00 <41> 38 d7 7c eb 84 d2 74 e7 48 89 df e8 cc aa 4e 00 eb dd be 04 00 RSP: 0018:ffff888085c47bd8 EFLAGS: 00000206 RAX: 0000000000000300 RBX: ffffffff89412b00 RCX: 1ffffffff1282560 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff89412b00 RBP: ffff888085c47c70 R08: 1ffffffff1282560 R09: fffffbfff1282561 R10: fffffbfff1282560 R11: ffffffff89412b03 R12: 00000000000000ff R13: fffffbfff1282560 R14: 1ffff11010b88f7d R15: 0000000000000003 FS: 00007fdd04086700(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fdd04064db8 CR3: 0000000090be0000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: queued_write_lock include/asm-generic/qrwlock.h:104 [inline] do_raw_write_lock+0x1d6/0x290 kernel/locking/spinlock_debug.c:203 __raw_write_lock_bh include/linux/rwlock_api_smp.h:204 [inline] _raw_write_lock_bh+0x3b/0x50 kernel/locking/spinlock.c:312 x25_insert_socket+0x21/0xe0 net/x25/af_x25.c:267 x25_bind+0x273/0x340 net/x25/af_x25.c:703 __sys_bind+0x23f/0x290 net/socket.c:1481 __do_sys_bind net/socket.c:1492 [inline] __se_sys_bind net/socket.c:1490 [inline] __x64_sys_bind+0x73/0xb0 net/socket.c:1490 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457e29 Fixes: 90c2729 ("X.25 remove bkl in bind") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: andrew hendry <andrew.hendry@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit 73e6ff7 ] Super-IO accesses may fail on a system with no or unmapped LPC bus. Unable to handle kernel paging request at virtual address ffffffbffee0002e pgd = ffffffc1d68d4000 [ffffffbffee0002e] *pgd=0000000000000000, *pud=0000000000000000 Internal error: Oops: 94000046 [#1] PREEMPT SMP Modules linked in: f71805f(+) hwmon CPU: 3 PID: 1659 Comm: insmod Not tainted 4.5.0+ rockchip-linux#88 Hardware name: linux,dummy-virt (DT) task: ffffffc1f6665400 ti: ffffffc1d6418000 task.ti: ffffffc1d6418000 PC is at f71805f_find+0x6c/0x358 [f71805f] Also, other drivers may attempt to access the LPC bus at the same time, resulting in undefined behavior. Use request_muxed_region() to ensure that IO access on the requested address space is supported, and to ensure that access by multiple drivers is synchronized. Fixes: e53004e ("hwmon: New f71805f driver") Reported-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reported-by: John Garry <john.garry@huawei.com> Cc: John Garry <john.garry@huawei.com> Acked-by: John Garry <john.garry@huawei.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit 73e6ff7 ] Super-IO accesses may fail on a system with no or unmapped LPC bus. Unable to handle kernel paging request at virtual address ffffffbffee0002e pgd = ffffffc1d68d4000 [ffffffbffee0002e] *pgd=0000000000000000, *pud=0000000000000000 Internal error: Oops: 94000046 [#1] PREEMPT SMP Modules linked in: f71805f(+) hwmon CPU: 3 PID: 1659 Comm: insmod Not tainted 4.5.0+ #88 Hardware name: linux,dummy-virt (DT) task: ffffffc1f6665400 ti: ffffffc1d6418000 task.ti: ffffffc1d6418000 PC is at f71805f_find+0x6c/0x358 [f71805f] Also, other drivers may attempt to access the LPC bus at the same time, resulting in undefined behavior. Use request_muxed_region() to ensure that IO access on the requested address space is supported, and to ensure that access by multiple drivers is synchronized. Fixes: e53004e ("hwmon: New f71805f driver") Reported-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reported-by: John Garry <john.garry@huawei.com> Cc: John Garry <john.garry@huawei.com> Acked-by: John Garry <john.garry@huawei.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Sasha Levin <sashal@kernel.org>

sysbot/KMSAN reported an uninit-value in recvmsg() that I tracked down to tipc_sk_set_orig_addr(), missing srcaddr->member.scope initialization. This patches moves srcaddr->sock.scope init to follow fields order and ease future verifications. BUG: KMSAN: uninit-value in copy_to_user include/linux/uaccess.h:184 [inline] BUG: KMSAN: uninit-value in move_addr_to_user+0x32e/0x530 net/socket.c:226 CPU: 0 PID: 4549 Comm: syz-executor287 Not tainted 4.17.0-rc3+ rockchip-linux#88 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x185/0x1d0 lib/dump_stack.c:113 kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067 kmsan_internal_check_memory+0x135/0x1e0 mm/kmsan/kmsan.c:1157 kmsan_copy_to_user+0x69/0x160 mm/kmsan/kmsan.c:1199 copy_to_user include/linux/uaccess.h:184 [inline] move_addr_to_user+0x32e/0x530 net/socket.c:226 ___sys_recvmsg+0x4e2/0x810 net/socket.c:2285 __sys_recvmsg net/socket.c:2328 [inline] __do_sys_recvmsg net/socket.c:2338 [inline] __se_sys_recvmsg net/socket.c:2335 [inline] __x64_sys_recvmsg+0x325/0x460 net/socket.c:2335 do_syscall_64+0x154/0x220 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x4455e9 RSP: 002b:00007fe3bd36ddb8 EFLAGS: 00000246 ORIG_RAX: 000000000000002f RAX: ffffffffffffffda RBX: 00000000006dac24 RCX: 00000000004455e9 RDX: 0000000000002002 RSI: 0000000020000400 RDI: 0000000000000003 RBP: 00000000006dac20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff98ce4b6f R14: 00007fe3bd36e9c0 R15: 0000000000000003 Local variable description: ----addr@___sys_recvmsg Variable was created at: ___sys_recvmsg+0xd5/0x810 net/socket.c:2246 __sys_recvmsg net/socket.c:2328 [inline] __do_sys_recvmsg net/socket.c:2338 [inline] __se_sys_recvmsg net/socket.c:2335 [inline] __x64_sys_recvmsg+0x325/0x460 net/socket.c:2335 Byte 19 of 32 is uninitialized Fixes: 31c82a2 ("tipc: add second source address to recvmsg()/recvfrom()") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Cc: Jon Maloy <jon.maloy@ericsson.com> Cc: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>

commit fd72761 upstream. powerpc sets up PF_KTHREAD and PF_IO_WORKER with a NULL pt_regs, which from my (arguably very short) checking is not commonly done for other archs. This is fine, except when PF_IO_WORKER's have been created and the task does something that causes a coredump to be generated. Then we get this crash: Kernel attempted to read user page (160) - exploit attempt? (uid: 1000) BUG: Kernel NULL pointer dereference on read at 0x00000160 Faulting instruction address: 0xc0000000000c3a60 Oops: Kernel access of bad area, sig: 11 [#1] LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=32 NUMA pSeries Modules linked in: bochs drm_vram_helper drm_kms_helper xts binfmt_misc ecb ctr syscopyarea sysfillrect cbc sysimgblt drm_ttm_helper aes_generic ttm sg libaes evdev joydev virtio_balloon vmx_crypto gf128mul drm dm_mod fuse loop configfs drm_panel_orientation_quirks ip_tables x_tables autofs4 hid_generic usbhid hid xhci_pci xhci_hcd usbcore usb_common sd_mod CPU: 1 PID: 1982 Comm: ppc-crash Not tainted 6.3.0-rc2+ rockchip-linux#88 Hardware name: IBM pSeries (emulated by qemu) POWER9 (raw) 0x4e1202 0xf000005 of:SLOF,HEAD hv:linux,kvm pSeries NIP: c0000000000c3a60 LR: c000000000039944 CTR: c0000000000398e0 REGS: c0000000041833b0 TRAP: 0300 Not tainted (6.3.0-rc2+) MSR: 800000000280b033 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE> CR: 88082828 XER: 200400f8 ... NIP memcpy_power7+0x200/0x7d0 LR ppr_get+0x64/0xb0 Call Trace: ppr_get+0x40/0xb0 (unreliable) __regset_get+0x180/0x1f0 regset_get_alloc+0x64/0x90 elf_core_dump+0xb98/0x1b60 do_coredump+0x1c34/0x24a0 get_signal+0x71c/0x1410 do_notify_resume+0x140/0x6f0 interrupt_exit_user_prepare_main+0x29c/0x320 interrupt_exit_user_prepare+0x6c/0xa0 interrupt_return_srr_user+0x8/0x138 Because ppr_get() is trying to copy from a PF_IO_WORKER with a NULL pt_regs. Check for a valid pt_regs in both ppc_get/ppr_set, and return an error if not set. The actual error value doesn't seem to be important here, so just pick -EINVAL. Fixes: fa43981 ("powerpc/ptrace: Enable support for NT_PPPC_TAR, NT_PPC_PPR, NT_PPC_DSCR") Cc: stable@vger.kernel.org # v4.8+ Signed-off-by: Jens Axboe <axboe@kernel.dk> [mpe: Trim oops in change log, add Fixes & Cc stable] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/d9f63344-fe7c-56ae-b420-4a1a04a2ae4c@kernel.dk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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[Question] RK3288 (Tinkerboard) maximum ethernet MTU #88

[Question] RK3288 (Tinkerboard) maximum ethernet MTU #88

rfrht commented Apr 22, 2018

[Question] RK3288 (Tinkerboard) maximum ethernet MTU #88

[Question] RK3288 (Tinkerboard) maximum ethernet MTU #88

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rfrht commented Apr 22, 2018