linux.git/fs/io_uring.c, branch v5.10.109 Clone of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git io_uring: return back safer resurrect 2022-03-19T12:44:46+00:00 Pavel Begunkov asml.silence@gmail.com 2021-04-11T00:46:40+00:00 dc1163203ae6e24b86168390fe5b4a3295fcba7f commit f70865db5ff35f5ed0c7e9ef63e7cca3d4947f04 upstream. Revert of revert of "io_uring: wait potential ->release() on resurrect", which adds a helper for resurrect not racing completion reinit, as was removed because of a strange bug with no clear root or link to the patch. Was improved, instead of rcu_synchronize(), just wait_for_completion() because we're at 0 refs and it will happen very shortly. Specifically use non-interruptible version to ignore all pending signals that may have ended prior interruptible wait. This reverts commit cb5e1b81304e089ee3ca948db4d29f71902eb575. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/7a080c20f686d026efade810b116b72f88abaff9.1618101759.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Cc: Lee Jones <lee.jones@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit f70865db5ff35f5ed0c7e9ef63e7cca3d4947f04 upstream.

Revert of revert of "io_uring: wait potential ->release() on resurrect",
which adds a helper for resurrect not racing completion reinit, as was
removed because of a strange bug with no clear root or link to the
patch.

Was improved, instead of rcu_synchronize(), just wait_for_completion()
because we're at 0 refs and it will happen very shortly. Specifically
use non-interruptible version to ignore all pending signals that may
have ended prior interruptible wait.

This reverts commit cb5e1b81304e089ee3ca948db4d29f71902eb575.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/7a080c20f686d026efade810b116b72f88abaff9.1618101759.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Cc: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
io_uring: add a schedule point in io_add_buffers() 2022-03-02T10:42:49+00:00 Eric Dumazet edumazet@google.com 2022-02-15T04:10:03+00:00 4a93c6594613c3429b6f30136fff115c7f803af4 commit f240762f88b4b1b58561939ffd44837759756477 upstream. Looping ~65535 times doing kmalloc() calls can trigger soft lockups, especially with DEBUG features (like KASAN). [ 253.536212] watchdog: BUG: soft lockup - CPU#64 stuck for 26s! [b219417889:12575] [ 253.544433] Modules linked in: vfat fat i2c_mux_pca954x i2c_mux spidev cdc_acm xhci_pci xhci_hcd sha3_generic gq(O) [ 253.544451] CPU: 64 PID: 12575 Comm: b219417889 Tainted: G S O 5.17.0-smp-DEV #801 [ 253.544457] RIP: 0010:kernel_text_address (./include/asm-generic/sections.h:192 ./include/linux/kallsyms.h:29 kernel/extable.c:67 kernel/extable.c:98) [ 253.544464] Code: 0f 93 c0 48 c7 c1 e0 63 d7 a4 48 39 cb 0f 92 c1 20 c1 0f b6 c1 5b 5d c3 90 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 53 48 89 fb <48> c7 c0 00 00 80 a0 41 be 01 00 00 00 48 39 c7 72 0c 48 c7 c0 40 [ 253.544468] RSP: 0018:ffff8882d8baf4c0 EFLAGS: 00000246 [ 253.544471] RAX: 1ffff1105b175e00 RBX: ffffffffa13ef09a RCX: 00000000a13ef001 [ 253.544474] RDX: ffffffffa13ef09a RSI: ffff8882d8baf558 RDI: ffffffffa13ef09a [ 253.544476] RBP: ffff8882d8baf4d8 R08: ffff8882d8baf5e0 R09: 0000000000000004 [ 253.544479] R10: ffff8882d8baf5e8 R11: ffffffffa0d59a50 R12: ffff8882eab20380 [ 253.544481] R13: ffffffffa0d59a50 R14: dffffc0000000000 R15: 1ffff1105b175eb0 [ 253.544483] FS: 00000000016d3380(0000) GS:ffff88af48c00000(0000) knlGS:0000000000000000 [ 253.544486] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 253.544488] CR2: 00000000004af0f0 CR3: 00000002eabfa004 CR4: 00000000003706e0 [ 253.544491] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 253.544492] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 253.544494] Call Trace: [ 253.544496] <TASK> [ 253.544498] ? io_queue_sqe (fs/io_uring.c:7143) [ 253.544505] __kernel_text_address (kernel/extable.c:78) [ 253.544508] unwind_get_return_address (arch/x86/kernel/unwind_frame.c:19) [ 253.544514] arch_stack_walk (arch/x86/kernel/stacktrace.c:27) [ 253.544517] ? io_queue_sqe (fs/io_uring.c:7143) [ 253.544521] stack_trace_save (kernel/stacktrace.c:123) [ 253.544527] ____kasan_kmalloc (mm/kasan/common.c:39 mm/kasan/common.c:45 mm/kasan/common.c:436 mm/kasan/common.c:515) [ 253.544531] ? ____kasan_kmalloc (mm/kasan/common.c:39 mm/kasan/common.c:45 mm/kasan/common.c:436 mm/kasan/common.c:515) [ 253.544533] ? __kasan_kmalloc (mm/kasan/common.c:524) [ 253.544535] ? kmem_cache_alloc_trace (./include/linux/kasan.h:270 mm/slab.c:3567) [ 253.544541] ? io_issue_sqe (fs/io_uring.c:4556 fs/io_uring.c:4589 fs/io_uring.c:6828) [ 253.544544] ? __io_queue_sqe (fs/io_uring.c:?) [ 253.544551] __kasan_kmalloc (mm/kasan/common.c:524) [ 253.544553] kmem_cache_alloc_trace (./include/linux/kasan.h:270 mm/slab.c:3567) [ 253.544556] ? io_issue_sqe (fs/io_uring.c:4556 fs/io_uring.c:4589 fs/io_uring.c:6828) [ 253.544560] io_issue_sqe (fs/io_uring.c:4556 fs/io_uring.c:4589 fs/io_uring.c:6828) [ 253.544564] ? __kasan_slab_alloc (mm/kasan/common.c:45 mm/kasan/common.c:436 mm/kasan/common.c:469) [ 253.544567] ? __kasan_slab_alloc (mm/kasan/common.c:39 mm/kasan/common.c:45 mm/kasan/common.c:436 mm/kasan/common.c:469) [ 253.544569] ? kmem_cache_alloc_bulk (mm/slab.h:732 mm/slab.c:3546) [ 253.544573] ? __io_alloc_req_refill (fs/io_uring.c:2078) [ 253.544578] ? io_submit_sqes (fs/io_uring.c:7441) [ 253.544581] ? __se_sys_io_uring_enter (fs/io_uring.c:10154 fs/io_uring.c:10096) [ 253.544584] ? __x64_sys_io_uring_enter (fs/io_uring.c:10096) [ 253.544587] ? do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80) [ 253.544590] ? entry_SYSCALL_64_after_hwframe (??:?) [ 253.544596] __io_queue_sqe (fs/io_uring.c:?) [ 253.544600] io_queue_sqe (fs/io_uring.c:7143) [ 253.544603] io_submit_sqe (fs/io_uring.c:?) [ 253.544608] io_submit_sqes (fs/io_uring.c:?) [ 253.544612] __se_sys_io_uring_enter (fs/io_uring.c:10154 fs/io_uring.c:10096) [ 253.544616] __x64_sys_io_uring_enter (fs/io_uring.c:10096) [ 253.544619] do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80) [ 253.544623] entry_SYSCALL_64_after_hwframe (??:?) Fixes: ddf0322db79c ("io_uring: add IORING_OP_PROVIDE_BUFFERS") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Pavel Begunkov <asml.silence@gmail.com> Cc: io-uring <io-uring@vger.kernel.org> Reported-by: syzbot <syzkaller@googlegroups.com> Link: https://lore.kernel.org/r/20220215041003.2394784-1-eric.dumazet@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit f240762f88b4b1b58561939ffd44837759756477 upstream.

Looping ~65535 times doing kmalloc() calls can trigger soft lockups,
especially with DEBUG features (like KASAN).

[  253.536212] watchdog: BUG: soft lockup - CPU#64 stuck for 26s! [b219417889:12575]
[  253.544433] Modules linked in: vfat fat i2c_mux_pca954x i2c_mux spidev cdc_acm xhci_pci xhci_hcd sha3_generic gq(O)
[  253.544451] CPU: 64 PID: 12575 Comm: b219417889 Tainted: G S         O      5.17.0-smp-DEV #801
[  253.544457] RIP: 0010:kernel_text_address (./include/asm-generic/sections.h:192 ./include/linux/kallsyms.h:29 kernel/extable.c:67 kernel/extable.c:98)
[  253.544464] Code: 0f 93 c0 48 c7 c1 e0 63 d7 a4 48 39 cb 0f 92 c1 20 c1 0f b6 c1 5b 5d c3 90 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 53 48 89 fb <48> c7 c0 00 00 80 a0 41 be 01 00 00 00 48 39 c7 72 0c 48 c7 c0 40
[  253.544468] RSP: 0018:ffff8882d8baf4c0 EFLAGS: 00000246
[  253.544471] RAX: 1ffff1105b175e00 RBX: ffffffffa13ef09a RCX: 00000000a13ef001
[  253.544474] RDX: ffffffffa13ef09a RSI: ffff8882d8baf558 RDI: ffffffffa13ef09a
[  253.544476] RBP: ffff8882d8baf4d8 R08: ffff8882d8baf5e0 R09: 0000000000000004
[  253.544479] R10: ffff8882d8baf5e8 R11: ffffffffa0d59a50 R12: ffff8882eab20380
[  253.544481] R13: ffffffffa0d59a50 R14: dffffc0000000000 R15: 1ffff1105b175eb0
[  253.544483] FS:  00000000016d3380(0000) GS:ffff88af48c00000(0000) knlGS:0000000000000000
[  253.544486] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  253.544488] CR2: 00000000004af0f0 CR3: 00000002eabfa004 CR4: 00000000003706e0
[  253.544491] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  253.544492] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  253.544494] Call Trace:
[  253.544496]  <TASK>
[  253.544498] ? io_queue_sqe (fs/io_uring.c:7143)
[  253.544505] __kernel_text_address (kernel/extable.c:78)
[  253.544508] unwind_get_return_address (arch/x86/kernel/unwind_frame.c:19)
[  253.544514] arch_stack_walk (arch/x86/kernel/stacktrace.c:27)
[  253.544517] ? io_queue_sqe (fs/io_uring.c:7143)
[  253.544521] stack_trace_save (kernel/stacktrace.c:123)
[  253.544527] ____kasan_kmalloc (mm/kasan/common.c:39 mm/kasan/common.c:45 mm/kasan/common.c:436 mm/kasan/common.c:515)
[  253.544531] ? ____kasan_kmalloc (mm/kasan/common.c:39 mm/kasan/common.c:45 mm/kasan/common.c:436 mm/kasan/common.c:515)
[  253.544533] ? __kasan_kmalloc (mm/kasan/common.c:524)
[  253.544535] ? kmem_cache_alloc_trace (./include/linux/kasan.h:270 mm/slab.c:3567)
[  253.544541] ? io_issue_sqe (fs/io_uring.c:4556 fs/io_uring.c:4589 fs/io_uring.c:6828)
[  253.544544] ? __io_queue_sqe (fs/io_uring.c:?)
[  253.544551] __kasan_kmalloc (mm/kasan/common.c:524)
[  253.544553] kmem_cache_alloc_trace (./include/linux/kasan.h:270 mm/slab.c:3567)
[  253.544556] ? io_issue_sqe (fs/io_uring.c:4556 fs/io_uring.c:4589 fs/io_uring.c:6828)
[  253.544560] io_issue_sqe (fs/io_uring.c:4556 fs/io_uring.c:4589 fs/io_uring.c:6828)
[  253.544564] ? __kasan_slab_alloc (mm/kasan/common.c:45 mm/kasan/common.c:436 mm/kasan/common.c:469)
[  253.544567] ? __kasan_slab_alloc (mm/kasan/common.c:39 mm/kasan/common.c:45 mm/kasan/common.c:436 mm/kasan/common.c:469)
[  253.544569] ? kmem_cache_alloc_bulk (mm/slab.h:732 mm/slab.c:3546)
[  253.544573] ? __io_alloc_req_refill (fs/io_uring.c:2078)
[  253.544578] ? io_submit_sqes (fs/io_uring.c:7441)
[  253.544581] ? __se_sys_io_uring_enter (fs/io_uring.c:10154 fs/io_uring.c:10096)
[  253.544584] ? __x64_sys_io_uring_enter (fs/io_uring.c:10096)
[  253.544587] ? do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80)
[  253.544590] ? entry_SYSCALL_64_after_hwframe (??:?)
[  253.544596] __io_queue_sqe (fs/io_uring.c:?)
[  253.544600] io_queue_sqe (fs/io_uring.c:7143)
[  253.544603] io_submit_sqe (fs/io_uring.c:?)
[  253.544608] io_submit_sqes (fs/io_uring.c:?)
[  253.544612] __se_sys_io_uring_enter (fs/io_uring.c:10154 fs/io_uring.c:10096)
[  253.544616] __x64_sys_io_uring_enter (fs/io_uring.c:10096)
[  253.544619] do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80)
[  253.544623] entry_SYSCALL_64_after_hwframe (??:?)

Fixes: ddf0322db79c ("io_uring: add IORING_OP_PROVIDE_BUFFERS")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Pavel Begunkov <asml.silence@gmail.com>
Cc: io-uring <io-uring@vger.kernel.org>
Reported-by: syzbot <syzkaller@googlegroups.com>
Link: https://lore.kernel.org/r/20220215041003.2394784-1-eric.dumazet@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Revert "io_uring: reinforce cancel on flush during exit" 2021-11-06T13:10:08+00:00 Lee Jones lee.jones@linaro.org 2021-11-02T15:49:30+00:00 748786564a358945922aa43a5b90710c81ed133e This reverts commit 88dbd085a51ec78c83dde79ad63bca8aa4272a9d. Causes the following Syzkaller reported issue: BUG: kernel NULL pointer dereference, address: 0000000000000010 PGD 0 P4D 0 Oops: 0002 [#1] PREEMPT SMP KASAN CPU: 1 PID: 546 Comm: syz-executor631 Tainted: G B 5.10.76-syzkaller-01178-g4944ec82ebb9 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:arch_atomic_try_cmpxchg syzkaller/managers/android-5-10/kernel/./arch/x86/include/asm/atomic.h:202 [inline] RIP: 0010:atomic_try_cmpxchg_acquire syzkaller/managers/android-5-10/kernel/./include/asm-generic/atomic-instrumented.h:707 [inline] RIP: 0010:queued_spin_lock syzkaller/managers/android-5-10/kernel/./include/asm-generic/qspinlock.h:82 [inline] RIP: 0010:do_raw_spin_lock_flags syzkaller/managers/android-5-10/kernel/./include/linux/spinlock.h:195 [inline] RIP: 0010:__raw_spin_lock_irqsave syzkaller/managers/android-5-10/kernel/./include/linux/spinlock_api_smp.h:119 [inline] RIP: 0010:_raw_spin_lock_irqsave+0x10d/0x210 syzkaller/managers/android-5-10/kernel/kernel/locking/spinlock.c:159 Code: 00 00 00 e8 d5 29 09 fd 4c 89 e7 be 04 00 00 00 e8 c8 29 09 fd 42 8a 04 3b 84 c0 0f 85 be 00 00 00 8b 44 24 40 b9 01 00 00 00 <f0> 41 0f b1 4d 00 75 45 48 c7 44 24 20 0e 36 e0 45 4b c7 04 37 00 RSP: 0018:ffffc90000f174e0 EFLAGS: 00010097 RAX: 0000000000000000 RBX: 1ffff920001e2ea4 RCX: 0000000000000001 RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc90000f17520 RBP: ffffc90000f175b0 R08: dffffc0000000000 R09: 0000000000000003 R10: fffff520001e2ea5 R11: 0000000000000004 R12: ffffc90000f17520 R13: 0000000000000010 R14: 1ffff920001e2ea0 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000010 CR3: 000000000640f000 CR4: 00000000003506a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: prepare_to_wait+0x9c/0x290 syzkaller/managers/android-5-10/kernel/kernel/sched/wait.c:248 io_uring_cancel_files syzkaller/managers/android-5-10/kernel/fs/io_uring.c:8690 [inline] io_uring_cancel_task_requests+0x16a9/0x1ed0 syzkaller/managers/android-5-10/kernel/fs/io_uring.c:8760 io_uring_flush+0x170/0x6d0 syzkaller/managers/android-5-10/kernel/fs/io_uring.c:8923 filp_close+0xb0/0x150 syzkaller/managers/android-5-10/kernel/fs/open.c:1319 close_files syzkaller/managers/android-5-10/kernel/fs/file.c:401 [inline] put_files_struct+0x1d4/0x350 syzkaller/managers/android-5-10/kernel/fs/file.c:429 exit_files+0x80/0xa0 syzkaller/managers/android-5-10/kernel/fs/file.c:458 do_exit+0x6d9/0x23a0 syzkaller/managers/android-5-10/kernel/kernel/exit.c:808 do_group_exit+0x16a/0x2d0 syzkaller/managers/android-5-10/kernel/kernel/exit.c:910 get_signal+0x133e/0x1f80 syzkaller/managers/android-5-10/kernel/kernel/signal.c:2790 arch_do_signal+0x8d/0x620 syzkaller/managers/android-5-10/kernel/arch/x86/kernel/signal.c:805 exit_to_user_mode_loop syzkaller/managers/android-5-10/kernel/kernel/entry/common.c:161 [inline] exit_to_user_mode_prepare+0xaa/0xe0 syzkaller/managers/android-5-10/kernel/kernel/entry/common.c:191 syscall_exit_to_user_mode+0x24/0x40 syzkaller/managers/android-5-10/kernel/kernel/entry/common.c:266 do_syscall_64+0x3d/0x70 syzkaller/managers/android-5-10/kernel/arch/x86/entry/common.c:56 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7fc6d1589a89 Code: Unable to access opcode bytes at RIP 0x7fc6d1589a5f. RSP: 002b:00007ffd2b5da728 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffdfc RBX: 0000000000005193 RCX: 00007fc6d1589a89 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fc6d161142c RBP: 0000000000000032 R08: 00007ffd2b5eb0b8 R09: 0000000000000000 R10: 00007ffd2b5da750 R11: 0000000000000246 R12: 00007fc6d161142c R13: 00007ffd2b5da750 R14: 00007ffd2b5da770 R15: 0000000000000000 Modules linked in: CR2: 0000000000000010 ---[ end trace fe8044f7dc4d8d65 ]--- RIP: 0010:arch_atomic_try_cmpxchg syzkaller/managers/android-5-10/kernel/./arch/x86/include/asm/atomic.h:202 [inline] RIP: 0010:atomic_try_cmpxchg_acquire syzkaller/managers/android-5-10/kernel/./include/asm-generic/atomic-instrumented.h:707 [inline] RIP: 0010:queued_spin_lock syzkaller/managers/android-5-10/kernel/./include/asm-generic/qspinlock.h:82 [inline] RIP: 0010:do_raw_spin_lock_flags syzkaller/managers/android-5-10/kernel/./include/linux/spinlock.h:195 [inline] RIP: 0010:__raw_spin_lock_irqsave syzkaller/managers/android-5-10/kernel/./include/linux/spinlock_api_smp.h:119 [inline] RIP: 0010:_raw_spin_lock_irqsave+0x10d/0x210 syzkaller/managers/android-5-10/kernel/kernel/locking/spinlock.c:159 Code: 00 00 00 e8 d5 29 09 fd 4c 89 e7 be 04 00 00 00 e8 c8 29 09 fd 42 8a 04 3b 84 c0 0f 85 be 00 00 00 8b 44 24 40 b9 01 00 00 00 <f0> 41 0f b1 4d 00 75 45 48 c7 44 24 20 0e 36 e0 45 4b c7 04 37 00 RSP: 0018:ffffc90000f174e0 EFLAGS: 00010097 RAX: 0000000000000000 RBX: 1ffff920001e2ea4 RCX: 0000000000000001 RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc90000f17520 RBP: ffffc90000f175b0 R08: dffffc0000000000 R09: 0000000000000003 R10: fffff520001e2ea5 R11: 0000000000000004 R12: ffffc90000f17520 R13: 0000000000000010 R14: 1ffff920001e2ea0 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000010 CR3: 000000000640f000 CR4: 00000000003506a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess), 1 bytes skipped: 0: 00 00 add %al,(%rax) 2: e8 d5 29 09 fd callq 0xfd0929dc 7: 4c 89 e7 mov %r12,%rdi a: be 04 00 00 00 mov $0x4,%esi f: e8 c8 29 09 fd callq 0xfd0929dc 14: 42 8a 04 3b mov (%rbx,%r15,1),%al 18: 84 c0 test %al,%al 1a: 0f 85 be 00 00 00 jne 0xde 20: 8b 44 24 40 mov 0x40(%rsp),%eax 24: b9 01 00 00 00 mov $0x1,%ecx * 29: f0 41 0f b1 4d 00 lock cmpxchg %ecx,0x0(%r13) <-- trapping instruction 2f: 75 45 jne 0x76 31: 48 c7 44 24 20 0e 36 movq $0x45e0360e,0x20(%rsp) 38: e0 45 3a: 4b rex.WXB 3b: c7 .byte 0xc7 3c: 04 37 add $0x37,%al Link: https://syzkaller.appspot.com/bug?extid=b0003676644cf0d6acc4 Reported-by: syzbot+b0003676644cf0d6acc4@syzkaller.appspotmail.com Signed-off-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
This reverts commit 88dbd085a51ec78c83dde79ad63bca8aa4272a9d.

Causes the following Syzkaller reported issue:

BUG: kernel NULL pointer dereference, address: 0000000000000010
PGD 0 P4D 0
Oops: 0002 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 546 Comm: syz-executor631 Tainted: G    B             5.10.76-syzkaller-01178-g4944ec82ebb9 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:arch_atomic_try_cmpxchg syzkaller/managers/android-5-10/kernel/./arch/x86/include/asm/atomic.h:202 [inline]
RIP: 0010:atomic_try_cmpxchg_acquire syzkaller/managers/android-5-10/kernel/./include/asm-generic/atomic-instrumented.h:707 [inline]
RIP: 0010:queued_spin_lock syzkaller/managers/android-5-10/kernel/./include/asm-generic/qspinlock.h:82 [inline]
RIP: 0010:do_raw_spin_lock_flags syzkaller/managers/android-5-10/kernel/./include/linux/spinlock.h:195 [inline]
RIP: 0010:__raw_spin_lock_irqsave syzkaller/managers/android-5-10/kernel/./include/linux/spinlock_api_smp.h:119 [inline]
RIP: 0010:_raw_spin_lock_irqsave+0x10d/0x210 syzkaller/managers/android-5-10/kernel/kernel/locking/spinlock.c:159
Code: 00 00 00 e8 d5 29 09 fd 4c 89 e7 be 04 00 00 00 e8 c8 29 09 fd 42 8a 04 3b 84 c0 0f 85 be 00 00 00 8b 44 24 40 b9 01 00 00 00 <f0> 41 0f b1 4d 00 75 45 48 c7 44 24 20 0e 36 e0 45 4b c7 04 37 00
RSP: 0018:ffffc90000f174e0 EFLAGS: 00010097
RAX: 0000000000000000 RBX: 1ffff920001e2ea4 RCX: 0000000000000001
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc90000f17520
RBP: ffffc90000f175b0 R08: dffffc0000000000 R09: 0000000000000003
R10: fffff520001e2ea5 R11: 0000000000000004 R12: ffffc90000f17520
R13: 0000000000000010 R14: 1ffff920001e2ea0 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000010 CR3: 000000000640f000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 prepare_to_wait+0x9c/0x290 syzkaller/managers/android-5-10/kernel/kernel/sched/wait.c:248
 io_uring_cancel_files syzkaller/managers/android-5-10/kernel/fs/io_uring.c:8690 [inline]
 io_uring_cancel_task_requests+0x16a9/0x1ed0 syzkaller/managers/android-5-10/kernel/fs/io_uring.c:8760
 io_uring_flush+0x170/0x6d0 syzkaller/managers/android-5-10/kernel/fs/io_uring.c:8923
 filp_close+0xb0/0x150 syzkaller/managers/android-5-10/kernel/fs/open.c:1319
 close_files syzkaller/managers/android-5-10/kernel/fs/file.c:401 [inline]
 put_files_struct+0x1d4/0x350 syzkaller/managers/android-5-10/kernel/fs/file.c:429
 exit_files+0x80/0xa0 syzkaller/managers/android-5-10/kernel/fs/file.c:458
 do_exit+0x6d9/0x23a0 syzkaller/managers/android-5-10/kernel/kernel/exit.c:808
 do_group_exit+0x16a/0x2d0 syzkaller/managers/android-5-10/kernel/kernel/exit.c:910
 get_signal+0x133e/0x1f80 syzkaller/managers/android-5-10/kernel/kernel/signal.c:2790
 arch_do_signal+0x8d/0x620 syzkaller/managers/android-5-10/kernel/arch/x86/kernel/signal.c:805
 exit_to_user_mode_loop syzkaller/managers/android-5-10/kernel/kernel/entry/common.c:161 [inline]
 exit_to_user_mode_prepare+0xaa/0xe0 syzkaller/managers/android-5-10/kernel/kernel/entry/common.c:191
 syscall_exit_to_user_mode+0x24/0x40 syzkaller/managers/android-5-10/kernel/kernel/entry/common.c:266
 do_syscall_64+0x3d/0x70 syzkaller/managers/android-5-10/kernel/arch/x86/entry/common.c:56
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7fc6d1589a89
Code: Unable to access opcode bytes at RIP 0x7fc6d1589a5f.
RSP: 002b:00007ffd2b5da728 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffdfc RBX: 0000000000005193 RCX: 00007fc6d1589a89
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fc6d161142c
RBP: 0000000000000032 R08: 00007ffd2b5eb0b8 R09: 0000000000000000
R10: 00007ffd2b5da750 R11: 0000000000000246 R12: 00007fc6d161142c
R13: 00007ffd2b5da750 R14: 00007ffd2b5da770 R15: 0000000000000000
Modules linked in:
CR2: 0000000000000010
---[ end trace fe8044f7dc4d8d65 ]---
RIP: 0010:arch_atomic_try_cmpxchg syzkaller/managers/android-5-10/kernel/./arch/x86/include/asm/atomic.h:202 [inline]
RIP: 0010:atomic_try_cmpxchg_acquire syzkaller/managers/android-5-10/kernel/./include/asm-generic/atomic-instrumented.h:707 [inline]
RIP: 0010:queued_spin_lock syzkaller/managers/android-5-10/kernel/./include/asm-generic/qspinlock.h:82 [inline]
RIP: 0010:do_raw_spin_lock_flags syzkaller/managers/android-5-10/kernel/./include/linux/spinlock.h:195 [inline]
RIP: 0010:__raw_spin_lock_irqsave syzkaller/managers/android-5-10/kernel/./include/linux/spinlock_api_smp.h:119 [inline]
RIP: 0010:_raw_spin_lock_irqsave+0x10d/0x210 syzkaller/managers/android-5-10/kernel/kernel/locking/spinlock.c:159
Code: 00 00 00 e8 d5 29 09 fd 4c 89 e7 be 04 00 00 00 e8 c8 29 09 fd 42 8a 04 3b 84 c0 0f 85 be 00 00 00 8b 44 24 40 b9 01 00 00 00 <f0> 41 0f b1 4d 00 75 45 48 c7 44 24 20 0e 36 e0 45 4b c7 04 37 00
RSP: 0018:ffffc90000f174e0 EFLAGS: 00010097
RAX: 0000000000000000 RBX: 1ffff920001e2ea4 RCX: 0000000000000001
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc90000f17520
RBP: ffffc90000f175b0 R08: dffffc0000000000 R09: 0000000000000003
R10: fffff520001e2ea5 R11: 0000000000000004 R12: ffffc90000f17520
R13: 0000000000000010 R14: 1ffff920001e2ea0 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000010 CR3: 000000000640f000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess), 1 bytes skipped:
   0:	00 00                	add    %al,(%rax)
   2:	e8 d5 29 09 fd       	callq  0xfd0929dc
   7:	4c 89 e7             	mov    %r12,%rdi
   a:	be 04 00 00 00       	mov    $0x4,%esi
   f:	e8 c8 29 09 fd       	callq  0xfd0929dc
  14:	42 8a 04 3b          	mov    (%rbx,%r15,1),%al
  18:	84 c0                	test   %al,%al
  1a:	0f 85 be 00 00 00    	jne    0xde
  20:	8b 44 24 40          	mov    0x40(%rsp),%eax
  24:	b9 01 00 00 00       	mov    $0x1,%ecx
* 29:	f0 41 0f b1 4d 00    	lock cmpxchg %ecx,0x0(%r13) <-- trapping instruction
  2f:	75 45                	jne    0x76
  31:	48 c7 44 24 20 0e 36 	movq   $0x45e0360e,0x20(%rsp)
  38:	e0 45
  3a:	4b                   	rex.WXB
  3b:	c7                   	.byte 0xc7
  3c:	04 37                	add    $0x37,%al

Link: https://syzkaller.appspot.com/bug?extid=b0003676644cf0d6acc4
Reported-by: syzbot+b0003676644cf0d6acc4@syzkaller.appspotmail.com
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
io_uring: don't take uring_lock during iowq cancel 2021-11-02T18:48:18+00:00 Pavel Begunkov asml.silence@gmail.com 2021-02-18T22:32:51+00:00 3f2c12ec8a3f992c528c7ad83f7272122dfe8d84 commit 792bb6eb862333658bf1bd2260133f0507e2da8d upstream. [ 97.866748] a.out/2890 is trying to acquire lock: [ 97.867829] ffff8881046763e8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_wq_submit_work+0x155/0x240 [ 97.869735] [ 97.869735] but task is already holding lock: [ 97.871033] ffff88810dfe0be8 (&ctx->uring_lock){+.+.}-{3:3}, at: __x64_sys_io_uring_enter+0x3f0/0x5b0 [ 97.873074] [ 97.873074] other info that might help us debug this: [ 97.874520] Possible unsafe locking scenario: [ 97.874520] [ 97.875845] CPU0 [ 97.876440] ---- [ 97.877048] lock(&ctx->uring_lock); [ 97.877961] lock(&ctx->uring_lock); [ 97.878881] [ 97.878881] *** DEADLOCK *** [ 97.878881] [ 97.880341] May be due to missing lock nesting notation [ 97.880341] [ 97.881952] 1 lock held by a.out/2890: [ 97.882873] #0: ffff88810dfe0be8 (&ctx->uring_lock){+.+.}-{3:3}, at: __x64_sys_io_uring_enter+0x3f0/0x5b0 [ 97.885108] [ 97.885108] stack backtrace: [ 97.890457] Call Trace: [ 97.891121] dump_stack+0xac/0xe3 [ 97.891972] __lock_acquire+0xab6/0x13a0 [ 97.892940] lock_acquire+0x2c3/0x390 [ 97.894894] __mutex_lock+0xae/0x9f0 [ 97.901101] io_wq_submit_work+0x155/0x240 [ 97.902112] io_wq_cancel_cb+0x162/0x490 [ 97.904126] io_async_find_and_cancel+0x3b/0x140 [ 97.905247] io_issue_sqe+0x86d/0x13e0 [ 97.909122] __io_queue_sqe+0x10b/0x550 [ 97.913971] io_queue_sqe+0x235/0x470 [ 97.914894] io_submit_sqes+0xcce/0xf10 [ 97.917872] __x64_sys_io_uring_enter+0x3fb/0x5b0 [ 97.921424] do_syscall_64+0x2d/0x40 [ 97.922329] entry_SYSCALL_64_after_hwframe+0x44/0xa9 While holding uring_lock, e.g. from inline execution, async cancel request may attempt cancellations through io_wq_submit_work, which may try to grab a lock. Delay it to task_work, so we do it from a clean context and don't have to worry about locking. Cc: <stable@vger.kernel.org> # 5.5+ Fixes: c07e6719511e ("io_uring: hold uring_lock while completing failed polled io in io_wq_submit_work()") Reported-by: Abaci <abaci@linux.alibaba.com> Reported-by: Hao Xu <haoxu@linux.alibaba.com> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> [Lee: The first hunk solves a different (double free) issue in v5.10. Only the first hunk of the original patch is relevant to v5.10 AND the first hunk of the original patch is only relevant to v5.10] Reported-by: syzbot+59d8a1f4e60c20c066cf@syzkaller.appspotmail.com Signed-off-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 792bb6eb862333658bf1bd2260133f0507e2da8d upstream.

[   97.866748] a.out/2890 is trying to acquire lock:
[   97.867829] ffff8881046763e8 (&ctx->uring_lock){+.+.}-{3:3}, at:
io_wq_submit_work+0x155/0x240
[   97.869735]
[   97.869735] but task is already holding lock:
[   97.871033] ffff88810dfe0be8 (&ctx->uring_lock){+.+.}-{3:3}, at:
__x64_sys_io_uring_enter+0x3f0/0x5b0
[   97.873074]
[   97.873074] other info that might help us debug this:
[   97.874520]  Possible unsafe locking scenario:
[   97.874520]
[   97.875845]        CPU0
[   97.876440]        ----
[   97.877048]   lock(&ctx->uring_lock);
[   97.877961]   lock(&ctx->uring_lock);
[   97.878881]
[   97.878881]  *** DEADLOCK ***
[   97.878881]
[   97.880341]  May be due to missing lock nesting notation
[   97.880341]
[   97.881952] 1 lock held by a.out/2890:
[   97.882873]  #0: ffff88810dfe0be8 (&ctx->uring_lock){+.+.}-{3:3}, at:
__x64_sys_io_uring_enter+0x3f0/0x5b0
[   97.885108]
[   97.885108] stack backtrace:
[   97.890457] Call Trace:
[   97.891121]  dump_stack+0xac/0xe3
[   97.891972]  __lock_acquire+0xab6/0x13a0
[   97.892940]  lock_acquire+0x2c3/0x390
[   97.894894]  __mutex_lock+0xae/0x9f0
[   97.901101]  io_wq_submit_work+0x155/0x240
[   97.902112]  io_wq_cancel_cb+0x162/0x490
[   97.904126]  io_async_find_and_cancel+0x3b/0x140
[   97.905247]  io_issue_sqe+0x86d/0x13e0
[   97.909122]  __io_queue_sqe+0x10b/0x550
[   97.913971]  io_queue_sqe+0x235/0x470
[   97.914894]  io_submit_sqes+0xcce/0xf10
[   97.917872]  __x64_sys_io_uring_enter+0x3fb/0x5b0
[   97.921424]  do_syscall_64+0x2d/0x40
[   97.922329]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

While holding uring_lock, e.g. from inline execution, async cancel
request may attempt cancellations through io_wq_submit_work, which may
try to grab a lock. Delay it to task_work, so we do it from a clean
context and don't have to worry about locking.

Cc: <stable@vger.kernel.org> # 5.5+
Fixes: c07e6719511e ("io_uring: hold uring_lock while completing failed polled io in io_wq_submit_work()")
Reported-by: Abaci <abaci@linux.alibaba.com>
Reported-by: Hao Xu <haoxu@linux.alibaba.com>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
[Lee: The first hunk solves a different (double free) issue in v5.10.
      Only the first hunk of the original patch is relevant to v5.10 AND
      the first hunk of the original patch is only relevant to v5.10]
Reported-by: syzbot+59d8a1f4e60c20c066cf@syzkaller.appspotmail.com
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
io_uring: fix splice_fd_in checks backport typo 2021-10-27T07:56:46+00:00 Kamal Mostafa kamal@canonical.com 2021-10-18T17:18:08+00:00 f59da9f7efa73a31b6287bd9b8f03a8d536e524f The linux-5.10.y backport of commit "io_uring: add ->splice_fd_in checks" includes a typo: "|" where "||" should be. (The original upstream commit is fine.) Fixes: 54eb6211b979 ("io_uring: add ->splice_fd_in checks") Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: stable@vger.kernel.org # v5.10 Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
The linux-5.10.y backport of commit "io_uring: add ->splice_fd_in checks"
includes a typo: "|" where "||" should be. (The original upstream commit
is fine.)

Fixes: 54eb6211b979 ("io_uring: add ->splice_fd_in checks")
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: stable@vger.kernel.org # v5.10
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
io_uring: put provided buffer meta data under memcg accounting 2021-09-30T08:11:05+00:00 Jens Axboe axboe@kernel.dk 2021-09-24T13:39:08+00:00 ce092350b452f256bff4b39d74c80c221bf8b0cf [ Upstream commit 9990da93d2bf9892c2c14c958bef050d4e461a1a ] For each provided buffer, we allocate a struct io_buffer to hold the data associated with it. As a large number of buffers can be provided, account that data with memcg. Fixes: ddf0322db79c ("io_uring: add IORING_OP_PROVIDE_BUFFERS") Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 9990da93d2bf9892c2c14c958bef050d4e461a1a ]

For each provided buffer, we allocate a struct io_buffer to hold the
data associated with it. As a large number of buffers can be provided,
account that data with memcg.

Fixes: ddf0322db79c ("io_uring: add IORING_OP_PROVIDE_BUFFERS")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
io_uring: ensure symmetry in handling iter types in loop_rw_iter() 2021-09-22T10:27:54+00:00 Jens Axboe axboe@kernel.dk 2021-09-12T12:45:07+00:00 ce8f81b76d3bef7b9fe6c8f84d029ab898b19469 commit 16c8d2df7ec0eed31b7d3b61cb13206a7fb930cc upstream. When setting up the next segment, we check what type the iter is and handle it accordingly. However, when incrementing and processed amount we do not, and both iter advance and addr/len are adjusted, regardless of type. Split the increment side just like we do on the setup side. Fixes: 4017eb91a9e7 ("io_uring: make loop_rw_iter() use original user supplied pointers") Cc: stable@vger.kernel.org Reported-by: Valentina Palmiotti <vpalmiotti@gmail.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 16c8d2df7ec0eed31b7d3b61cb13206a7fb930cc upstream.

When setting up the next segment, we check what type the iter is and
handle it accordingly. However, when incrementing and processed amount
we do not, and both iter advance and addr/len are adjusted, regardless
of type. Split the increment side just like we do on the setup side.

Fixes: 4017eb91a9e7 ("io_uring: make loop_rw_iter() use original user supplied pointers")
Cc: stable@vger.kernel.org
Reported-by: Valentina Palmiotti <vpalmiotti@gmail.com>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
io_uring: remove duplicated io_size from rw 2021-09-18T11:40:35+00:00 Pavel Begunkov asml.silence@gmail.com 2020-11-07T13:16:26+00:00 9a4e7f9038660b7fd41280f9d97e6c722804bd1d [ Upstream commit 632546c4b5a4dad8e3ac456406c65c0db9a0b570 ] io_size and iov_count in io_read() and io_write() hold the same value, kill the last one. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 632546c4b5a4dad8e3ac456406c65c0db9a0b570 ]

io_size and iov_count in io_read() and io_write() hold the same value,
kill the last one.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
fs/io_uring Don't use the return value from import_iovec(). 2021-09-18T11:40:35+00:00 David Laight David.Laight@ACULAB.COM 2020-11-07T13:16:25+00:00 6930a2a5be5cbb0c202fcfa2773c95bd10a19197 [ Upstream commit 10fc72e43352753a08f9cf83aa5c40baec00d212 ] This is the only code that relies on import_iovec() returning iter.count on success. This allows a better interface to import_iovec(). Signed-off-by: David Laight <david.laight@aculab.com> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 10fc72e43352753a08f9cf83aa5c40baec00d212 ]

This is the only code that relies on import_iovec() returning
iter.count on success.
This allows a better interface to import_iovec().

Signed-off-by: David Laight <david.laight@aculab.com>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
io_uring: fail links of cancelled timeouts 2021-09-18T11:40:05+00:00 Pavel Begunkov asml.silence@gmail.com 2021-09-13T15:45:41+00:00 548ee201fb4a3c372a332284df3ecc21749918e1 commit 2ae2eb9dde18979b40629dd413b9adbd6c894cdf upstream. When we cancel a timeout we should mark it with REQ_F_FAIL, so linked requests are cancelled as well, but not queued for further execution. Cc: stable@vger.kernel.org Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/fff625b44eeced3a5cae79f60e6acf3fbdf8f990.1631192135.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 2ae2eb9dde18979b40629dd413b9adbd6c894cdf upstream.

When we cancel a timeout we should mark it with REQ_F_FAIL, so
linked requests are cancelled as well, but not queued for further
execution.

Cc: stable@vger.kernel.org
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/fff625b44eeced3a5cae79f60e6acf3fbdf8f990.1631192135.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>