* INFO: task hung in io_uring_setup
@ 2020-09-03 8:38 syzbot
[not found] ` <[email protected]>
0 siblings, 1 reply; 5+ messages in thread
From: syzbot @ 2020-09-03 8:38 UTC (permalink / raw)
To: axboe, io-uring, keescook, linux-fsdevel, linux-kernel, sgarzare,
syzkaller-bugs, viro
Hello,
syzbot found the following issue on:
HEAD commit: 4442749a Add linux-next specific files for 20200902
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=12f9e915900000
kernel config: https://syzkaller.appspot.com/x/.config?x=39134fcec6c78e33
dashboard link: https://syzkaller.appspot.com/bug?extid=107dd59d1efcaf3ffca4
compiler: gcc (GCC) 10.1.0-syz 20200507
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11594671900000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=111ca835900000
The issue was bisected to:
commit dfe127799f8e663c7e3e48b5275ca538b278177b
Author: Stefano Garzarella <[email protected]>
Date: Thu Aug 27 14:58:31 2020 +0000
io_uring: allow disabling rings during the creation
bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=11bc66c1900000
final oops: https://syzkaller.appspot.com/x/report.txt?x=13bc66c1900000
console output: https://syzkaller.appspot.com/x/log.txt?x=15bc66c1900000
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email protected]
Fixes: dfe127799f8e ("io_uring: allow disabling rings during the creation")
INFO: task syz-executor047:6853 blocked for more than 143 seconds.
Not tainted 5.9.0-rc3-next-20200902-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor047 state:D stack:28104 pid: 6853 ppid: 6847 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:3777 [inline]
__schedule+0xea9/0x2230 kernel/sched/core.c:4526
schedule+0xd0/0x2a0 kernel/sched/core.c:4601
schedule_timeout+0x1d8/0x250 kernel/time/timer.c:1855
do_wait_for_common kernel/sched/completion.c:85 [inline]
__wait_for_common kernel/sched/completion.c:106 [inline]
wait_for_common kernel/sched/completion.c:117 [inline]
wait_for_completion+0x163/0x260 kernel/sched/completion.c:138
io_sq_thread_stop fs/io_uring.c:6906 [inline]
io_finish_async fs/io_uring.c:6920 [inline]
io_sq_offload_create fs/io_uring.c:7595 [inline]
io_uring_create fs/io_uring.c:8671 [inline]
io_uring_setup+0x1495/0x29a0 fs/io_uring.c:8744
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x440299
Code: Bad RIP value.
RSP: 002b:00007ffc57cff668 EFLAGS: 00000246 ORIG_RAX: 00000000000001a9
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440299
RDX: 0000000000400b40 RSI: 0000000020000100 RDI: 0000000000003ffe
RBP: 00000000006ca018 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 0000000000401aa0
R13: 0000000000401b30 R14: 0000000000000000 R15: 0000000000000000
INFO: task io_uring-sq:6854 blocked for more than 143 seconds.
Not tainted 5.9.0-rc3-next-20200902-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:io_uring-sq state:D stack:31200 pid: 6854 ppid: 2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:3777 [inline]
__schedule+0xea9/0x2230 kernel/sched/core.c:4526
schedule+0xd0/0x2a0 kernel/sched/core.c:4601
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4660
kthread+0x2ac/0x4a0 kernel/kthread.c:285
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
Showing all locks held in the system:
1 lock held by khungtaskd/1174:
#0: ffffffff89c67980 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5829
3 locks held by in:imklog/6525:
#0: ffff8880a3de2df0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:930
#1: ffff8880907d8968 (&mm->mmap_lock#2){++++}-{3:3}, at: rq_lock kernel/sched/sched.h:1292 [inline]
#1: ffff8880907d8968 (&mm->mmap_lock#2){++++}-{3:3}, at: ttwu_queue kernel/sched/core.c:2698 [inline]
#1: ffff8880907d8968 (&mm->mmap_lock#2){++++}-{3:3}, at: try_to_wake_up+0x52b/0x12b0 kernel/sched/core.c:2978
#2: ffff8880ae620ec8 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x2fb/0x400 kernel/sched/psi.c:833
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 1174 Comm: khungtaskd Not tainted 5.9.0-rc3-next-20200902-syzkaller #0
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+0x198/0x1fd lib/dump_stack.c:118
nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105
nmi_trigger_cpumask_backtrace+0x1b3/0x223 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:147 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:253 [inline]
watchdog+0xd89/0xf30 kernel/hung_task.c:339
kthread+0x3b5/0x4a0 kernel/kthread.c:292
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 3901 Comm: systemd-journal Not tainted 5.9.0-rc3-next-20200902-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:unwind_next_frame+0x139a/0x1f90 arch/x86/kernel/unwind_orc.c:607
Code: 49 39 47 28 0f 85 3e f0 ff ff 80 3d df 2c 84 09 00 0f 85 31 f0 ff ff e9 06 18 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 14 24 <48> c1 ea 03 80 3c 02 00 0f 85 02 08 00 00 49 8d 7f 08 49 8b 6f 38
RSP: 0018:ffffc900040475f8 EFLAGS: 00000246
RAX: dffffc0000000000 RBX: 1ffff92000808ec7 RCX: 1ffff92000808ee2
RDX: ffffc90004047708 RSI: ffffc90004047aa8 RDI: ffffc90004047aa8
RBP: 0000000000000001 R08: ffffffff8b32a670 R09: 0000000000000001
R10: 000000000007201e R11: 0000000000000001 R12: ffffc90004047ac8
R13: ffffc90004047705 R14: ffffc90004047720 R15: ffffc900040476d0
FS: 00007efc659ac8c0(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007efc62d51000 CR3: 0000000093d6a000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
arch_stack_walk+0x81/0xf0 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:123
kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48
kasan_set_track mm/kasan/common.c:56 [inline]
__kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461
slab_post_alloc_hook mm/slab.h:517 [inline]
slab_alloc mm/slab.c:3312 [inline]
kmem_cache_alloc+0x13a/0x3a0 mm/slab.c:3482
kmem_cache_zalloc include/linux/slab.h:656 [inline]
__alloc_file+0x21/0x350 fs/file_table.c:101
alloc_empty_file+0x6d/0x170 fs/file_table.c:151
path_openat+0xe3/0x2730 fs/namei.c:3354
do_filp_open+0x17e/0x3c0 fs/namei.c:3395
do_sys_openat2+0x16d/0x420 fs/open.c:1168
do_sys_open fs/open.c:1184 [inline]
__do_sys_open fs/open.c:1192 [inline]
__se_sys_open fs/open.c:1188 [inline]
__x64_sys_open+0x119/0x1c0 fs/open.c:1188
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7efc64f3c840
Code: 73 01 c3 48 8b 0d 68 77 20 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 89 bb 20 00 00 75 10 b8 02 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 1e f6 ff ff 48 89 04 24
RSP: 002b:00007ffc45e60f18 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00007ffc45e61220 RCX: 00007efc64f3c840
RDX: 00000000000001a0 RSI: 0000000000080042 RDI: 00005626d683e6d0
RBP: 000000000000000d R08: 000000000000c0ff R09: 00000000ffffffff
R10: 0000000000000069 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00005626d6831040 R14: 00007ffc45e611e0 R15: 00005626d683e720
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at [email protected].
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
For information about bisection process see: https://goo.gl/tpsmEJ#bisection
syzbot can test patches for this issue, for details see:
https://goo.gl/tpsmEJ#testing-patches
^ permalink raw reply [flat|nested] 5+ messages in thread
[parent not found: <[email protected]>]
* Re: INFO: task hung in io_uring_setup [not found] ` <[email protected]> @ 2020-09-03 11:44 ` Jens Axboe 2020-10-30 10:01 ` Dmitry Vyukov 0 siblings, 1 reply; 5+ messages in thread From: Jens Axboe @ 2020-09-03 11:44 UTC (permalink / raw) To: Hillf Danton, syzbot Cc: io-uring, keescook, linux-fsdevel, linux-kernel, sgarzare, syzkaller-bugs, viro On 9/3/20 5:15 AM, Hillf Danton wrote: > > Thu, 03 Sep 2020 01:38:15 -0700 >> syzbot found the following issue on: >> >> HEAD commit: 4442749a Add linux-next specific files for 20200902 >> git tree: linux-next >> console output: https://syzkaller.appspot.com/x/log.txt?x=12f9e915900000 >> kernel config: https://syzkaller.appspot.com/x/.config?x=39134fcec6c78e33 >> dashboard link: https://syzkaller.appspot.com/bug?extid=107dd59d1efcaf3ffca4 >> compiler: gcc (GCC) 10.1.0-syz 20200507 >> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11594671900000 >> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=111ca835900000 >> >> The issue was bisected to: >> >> commit dfe127799f8e663c7e3e48b5275ca538b278177b >> Author: Stefano Garzarella <[email protected]> >> Date: Thu Aug 27 14:58:31 2020 +0000 >> >> io_uring: allow disabling rings during the creation >> >> bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=11bc66c1900000 >> final oops: https://syzkaller.appspot.com/x/report.txt?x=13bc66c1900000 >> console output: https://syzkaller.appspot.com/x/log.txt?x=15bc66c1900000 >> >> IMPORTANT: if you fix the issue, please add the following tag to the commit: >> Reported-by: [email protected] >> Fixes: dfe127799f8e ("io_uring: allow disabling rings during the creation") >> >> INFO: task syz-executor047:6853 blocked for more than 143 seconds. >> Not tainted 5.9.0-rc3-next-20200902-syzkaller #0 >> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. >> task:syz-executor047 state:D stack:28104 pid: 6853 ppid: 6847 flags:0x00004000 >> Call Trace: >> context_switch kernel/sched/core.c:3777 [inline] >> __schedule+0xea9/0x2230 kernel/sched/core.c:4526 >> schedule+0xd0/0x2a0 kernel/sched/core.c:4601 >> schedule_timeout+0x1d8/0x250 kernel/time/timer.c:1855 >> do_wait_for_common kernel/sched/completion.c:85 [inline] >> __wait_for_common kernel/sched/completion.c:106 [inline] >> wait_for_common kernel/sched/completion.c:117 [inline] >> wait_for_completion+0x163/0x260 kernel/sched/completion.c:138 >> io_sq_thread_stop fs/io_uring.c:6906 [inline] >> io_finish_async fs/io_uring.c:6920 [inline] >> io_sq_offload_create fs/io_uring.c:7595 [inline] >> io_uring_create fs/io_uring.c:8671 [inline] >> io_uring_setup+0x1495/0x29a0 fs/io_uring.c:8744 >> do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 >> entry_SYSCALL_64_after_hwframe+0x44/0xa9 >> RIP: 0033:0x440299 >> Code: Bad RIP value. >> RSP: 002b:00007ffc57cff668 EFLAGS: 00000246 ORIG_RAX: 00000000000001a9 >> RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440299 >> RDX: 0000000000400b40 RSI: 0000000020000100 RDI: 0000000000003ffe >> RBP: 00000000006ca018 R08: 0000000000000000 R09: 0000000000000000 >> R10: 00000000ffffffff R11: 0000000000000246 R12: 0000000000401aa0 >> R13: 0000000000401b30 R14: 0000000000000000 R15: 0000000000000000 >> INFO: task io_uring-sq:6854 blocked for more than 143 seconds. >> Not tainted 5.9.0-rc3-next-20200902-syzkaller #0 >> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. >> task:io_uring-sq state:D stack:31200 pid: 6854 ppid: 2 flags:0x00004000 >> Call Trace: >> context_switch kernel/sched/core.c:3777 [inline] >> __schedule+0xea9/0x2230 kernel/sched/core.c:4526 >> schedule+0xd0/0x2a0 kernel/sched/core.c:4601 >> schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4660 >> kthread+0x2ac/0x4a0 kernel/kthread.c:285 >> ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 >> >> Showing all locks held in the system: >> 1 lock held by khungtaskd/1174: >> #0: ffffffff89c67980 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5829 >> 3 locks held by in:imklog/6525: >> #0: ffff8880a3de2df0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:930 >> #1: ffff8880907d8968 (&mm->mmap_lock#2){++++}-{3:3}, at: rq_lock kernel/sched/sched.h:1292 [inline] >> #1: ffff8880907d8968 (&mm->mmap_lock#2){++++}-{3:3}, at: ttwu_queue kernel/sched/core.c:2698 [inline] >> #1: ffff8880907d8968 (&mm->mmap_lock#2){++++}-{3:3}, at: try_to_wake_up+0x52b/0x12b0 kernel/sched/core.c:2978 >> #2: ffff8880ae620ec8 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x2fb/0x400 kernel/sched/psi.c:833 >> >> ============================================= >> >> NMI backtrace for cpu 1 >> CPU: 1 PID: 1174 Comm: khungtaskd Not tainted 5.9.0-rc3-next-20200902-syzkaller #0 >> 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+0x198/0x1fd lib/dump_stack.c:118 >> nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105 >> nmi_trigger_cpumask_backtrace+0x1b3/0x223 lib/nmi_backtrace.c:62 >> trigger_all_cpu_backtrace include/linux/nmi.h:147 [inline] >> check_hung_uninterruptible_tasks kernel/hung_task.c:253 [inline] >> watchdog+0xd89/0xf30 kernel/hung_task.c:339 >> kthread+0x3b5/0x4a0 kernel/kthread.c:292 >> ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 >> Sending NMI from CPU 1 to CPUs 0: >> NMI backtrace for cpu 0 >> CPU: 0 PID: 3901 Comm: systemd-journal Not tainted 5.9.0-rc3-next-20200902-syzkaller #0 >> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 >> RIP: 0010:unwind_next_frame+0x139a/0x1f90 arch/x86/kernel/unwind_orc.c:607 >> Code: 49 39 47 28 0f 85 3e f0 ff ff 80 3d df 2c 84 09 00 0f 85 31 f0 ff ff e9 06 18 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 14 24 <48> c1 ea 03 80 3c 02 00 0f 85 02 08 00 00 49 8d 7f 08 49 8b 6f 38 >> RSP: 0018:ffffc900040475f8 EFLAGS: 00000246 >> RAX: dffffc0000000000 RBX: 1ffff92000808ec7 RCX: 1ffff92000808ee2 >> RDX: ffffc90004047708 RSI: ffffc90004047aa8 RDI: ffffc90004047aa8 >> RBP: 0000000000000001 R08: ffffffff8b32a670 R09: 0000000000000001 >> R10: 000000000007201e R11: 0000000000000001 R12: ffffc90004047ac8 >> R13: ffffc90004047705 R14: ffffc90004047720 R15: ffffc900040476d0 >> FS: 00007efc659ac8c0(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 >> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >> CR2: 00007efc62d51000 CR3: 0000000093d6a000 CR4: 00000000001506f0 >> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 >> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 >> Call Trace: >> arch_stack_walk+0x81/0xf0 arch/x86/kernel/stacktrace.c:25 >> stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:123 >> kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 >> kasan_set_track mm/kasan/common.c:56 [inline] >> __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461 >> slab_post_alloc_hook mm/slab.h:517 [inline] >> slab_alloc mm/slab.c:3312 [inline] >> kmem_cache_alloc+0x13a/0x3a0 mm/slab.c:3482 >> kmem_cache_zalloc include/linux/slab.h:656 [inline] >> __alloc_file+0x21/0x350 fs/file_table.c:101 >> alloc_empty_file+0x6d/0x170 fs/file_table.c:151 >> path_openat+0xe3/0x2730 fs/namei.c:3354 >> do_filp_open+0x17e/0x3c0 fs/namei.c:3395 >> do_sys_openat2+0x16d/0x420 fs/open.c:1168 >> do_sys_open fs/open.c:1184 [inline] >> __do_sys_open fs/open.c:1192 [inline] >> __se_sys_open fs/open.c:1188 [inline] >> __x64_sys_open+0x119/0x1c0 fs/open.c:1188 >> do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 >> entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > Add wakeup to make sure the wait for completion will be completed. > > --- a/fs/io_uring.c > +++ b/fs/io_uring.c > @@ -6903,6 +6903,7 @@ static int io_sqe_files_unregister(struc > static void io_sq_thread_stop(struct io_ring_ctx *ctx) > { > if (ctx->sqo_thread) { > + wake_up_process(ctx->sqo_thread); > wait_for_completion(&ctx->sq_thread_comp); > /* > * The park is a bit of a work-around, without it we get Yeah this looks reasonable, if the thread is attempted stopped if it was created de-activated and never started. Needs a comment to that effect. Care to add that and send it as a properly formatted patch (with commit message, etc)? -- Jens Axboe ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: INFO: task hung in io_uring_setup 2020-09-03 11:44 ` Jens Axboe @ 2020-10-30 10:01 ` Dmitry Vyukov 2020-10-30 14:01 ` Jens Axboe 0 siblings, 1 reply; 5+ messages in thread From: Dmitry Vyukov @ 2020-10-30 10:01 UTC (permalink / raw) To: Jens Axboe Cc: Hillf Danton, syzbot, io-uring, Kees Cook, linux-fsdevel, LKML, sgarzare, syzkaller-bugs, Al Viro On Thu, Sep 3, 2020 at 1:44 PM Jens Axboe <[email protected]> wrote: > > On 9/3/20 5:15 AM, Hillf Danton wrote: > > > > Thu, 03 Sep 2020 01:38:15 -0700 > >> syzbot found the following issue on: > >> > >> HEAD commit: 4442749a Add linux-next specific files for 20200902 > >> git tree: linux-next > >> console output: https://syzkaller.appspot.com/x/log.txt?x=12f9e915900000 > >> kernel config: https://syzkaller.appspot.com/x/.config?x=39134fcec6c78e33 > >> dashboard link: https://syzkaller.appspot.com/bug?extid=107dd59d1efcaf3ffca4 > >> compiler: gcc (GCC) 10.1.0-syz 20200507 > >> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11594671900000 > >> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=111ca835900000 > >> > >> The issue was bisected to: > >> > >> commit dfe127799f8e663c7e3e48b5275ca538b278177b > >> Author: Stefano Garzarella <[email protected]> > >> Date: Thu Aug 27 14:58:31 2020 +0000 > >> > >> io_uring: allow disabling rings during the creation > >> > >> bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=11bc66c1900000 > >> final oops: https://syzkaller.appspot.com/x/report.txt?x=13bc66c1900000 > >> console output: https://syzkaller.appspot.com/x/log.txt?x=15bc66c1900000 > >> > >> IMPORTANT: if you fix the issue, please add the following tag to the commit: > >> Reported-by: [email protected] > >> Fixes: dfe127799f8e ("io_uring: allow disabling rings during the creation") > >> > >> INFO: task syz-executor047:6853 blocked for more than 143 seconds. > >> Not tainted 5.9.0-rc3-next-20200902-syzkaller #0 > >> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > >> task:syz-executor047 state:D stack:28104 pid: 6853 ppid: 6847 flags:0x00004000 > >> Call Trace: > >> context_switch kernel/sched/core.c:3777 [inline] > >> __schedule+0xea9/0x2230 kernel/sched/core.c:4526 > >> schedule+0xd0/0x2a0 kernel/sched/core.c:4601 > >> schedule_timeout+0x1d8/0x250 kernel/time/timer.c:1855 > >> do_wait_for_common kernel/sched/completion.c:85 [inline] > >> __wait_for_common kernel/sched/completion.c:106 [inline] > >> wait_for_common kernel/sched/completion.c:117 [inline] > >> wait_for_completion+0x163/0x260 kernel/sched/completion.c:138 > >> io_sq_thread_stop fs/io_uring.c:6906 [inline] > >> io_finish_async fs/io_uring.c:6920 [inline] > >> io_sq_offload_create fs/io_uring.c:7595 [inline] > >> io_uring_create fs/io_uring.c:8671 [inline] > >> io_uring_setup+0x1495/0x29a0 fs/io_uring.c:8744 > >> do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 > >> entry_SYSCALL_64_after_hwframe+0x44/0xa9 > >> RIP: 0033:0x440299 > >> Code: Bad RIP value. > >> RSP: 002b:00007ffc57cff668 EFLAGS: 00000246 ORIG_RAX: 00000000000001a9 > >> RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440299 > >> RDX: 0000000000400b40 RSI: 0000000020000100 RDI: 0000000000003ffe > >> RBP: 00000000006ca018 R08: 0000000000000000 R09: 0000000000000000 > >> R10: 00000000ffffffff R11: 0000000000000246 R12: 0000000000401aa0 > >> R13: 0000000000401b30 R14: 0000000000000000 R15: 0000000000000000 > >> INFO: task io_uring-sq:6854 blocked for more than 143 seconds. > >> Not tainted 5.9.0-rc3-next-20200902-syzkaller #0 > >> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > >> task:io_uring-sq state:D stack:31200 pid: 6854 ppid: 2 flags:0x00004000 > >> Call Trace: > >> context_switch kernel/sched/core.c:3777 [inline] > >> __schedule+0xea9/0x2230 kernel/sched/core.c:4526 > >> schedule+0xd0/0x2a0 kernel/sched/core.c:4601 > >> schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4660 > >> kthread+0x2ac/0x4a0 kernel/kthread.c:285 > >> ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 > >> > >> Showing all locks held in the system: > >> 1 lock held by khungtaskd/1174: > >> #0: ffffffff89c67980 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5829 > >> 3 locks held by in:imklog/6525: > >> #0: ffff8880a3de2df0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:930 > >> #1: ffff8880907d8968 (&mm->mmap_lock#2){++++}-{3:3}, at: rq_lock kernel/sched/sched.h:1292 [inline] > >> #1: ffff8880907d8968 (&mm->mmap_lock#2){++++}-{3:3}, at: ttwu_queue kernel/sched/core.c:2698 [inline] > >> #1: ffff8880907d8968 (&mm->mmap_lock#2){++++}-{3:3}, at: try_to_wake_up+0x52b/0x12b0 kernel/sched/core.c:2978 > >> #2: ffff8880ae620ec8 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x2fb/0x400 kernel/sched/psi.c:833 > >> > >> ============================================= > >> > >> NMI backtrace for cpu 1 > >> CPU: 1 PID: 1174 Comm: khungtaskd Not tainted 5.9.0-rc3-next-20200902-syzkaller #0 > >> 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+0x198/0x1fd lib/dump_stack.c:118 > >> nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105 > >> nmi_trigger_cpumask_backtrace+0x1b3/0x223 lib/nmi_backtrace.c:62 > >> trigger_all_cpu_backtrace include/linux/nmi.h:147 [inline] > >> check_hung_uninterruptible_tasks kernel/hung_task.c:253 [inline] > >> watchdog+0xd89/0xf30 kernel/hung_task.c:339 > >> kthread+0x3b5/0x4a0 kernel/kthread.c:292 > >> ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 > >> Sending NMI from CPU 1 to CPUs 0: > >> NMI backtrace for cpu 0 > >> CPU: 0 PID: 3901 Comm: systemd-journal Not tainted 5.9.0-rc3-next-20200902-syzkaller #0 > >> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > >> RIP: 0010:unwind_next_frame+0x139a/0x1f90 arch/x86/kernel/unwind_orc.c:607 > >> Code: 49 39 47 28 0f 85 3e f0 ff ff 80 3d df 2c 84 09 00 0f 85 31 f0 ff ff e9 06 18 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 14 24 <48> c1 ea 03 80 3c 02 00 0f 85 02 08 00 00 49 8d 7f 08 49 8b 6f 38 > >> RSP: 0018:ffffc900040475f8 EFLAGS: 00000246 > >> RAX: dffffc0000000000 RBX: 1ffff92000808ec7 RCX: 1ffff92000808ee2 > >> RDX: ffffc90004047708 RSI: ffffc90004047aa8 RDI: ffffc90004047aa8 > >> RBP: 0000000000000001 R08: ffffffff8b32a670 R09: 0000000000000001 > >> R10: 000000000007201e R11: 0000000000000001 R12: ffffc90004047ac8 > >> R13: ffffc90004047705 R14: ffffc90004047720 R15: ffffc900040476d0 > >> FS: 00007efc659ac8c0(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 > >> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > >> CR2: 00007efc62d51000 CR3: 0000000093d6a000 CR4: 00000000001506f0 > >> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > >> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > >> Call Trace: > >> arch_stack_walk+0x81/0xf0 arch/x86/kernel/stacktrace.c:25 > >> stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:123 > >> kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 > >> kasan_set_track mm/kasan/common.c:56 [inline] > >> __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461 > >> slab_post_alloc_hook mm/slab.h:517 [inline] > >> slab_alloc mm/slab.c:3312 [inline] > >> kmem_cache_alloc+0x13a/0x3a0 mm/slab.c:3482 > >> kmem_cache_zalloc include/linux/slab.h:656 [inline] > >> __alloc_file+0x21/0x350 fs/file_table.c:101 > >> alloc_empty_file+0x6d/0x170 fs/file_table.c:151 > >> path_openat+0xe3/0x2730 fs/namei.c:3354 > >> do_filp_open+0x17e/0x3c0 fs/namei.c:3395 > >> do_sys_openat2+0x16d/0x420 fs/open.c:1168 > >> do_sys_open fs/open.c:1184 [inline] > >> __do_sys_open fs/open.c:1192 [inline] > >> __se_sys_open fs/open.c:1188 [inline] > >> __x64_sys_open+0x119/0x1c0 fs/open.c:1188 > >> do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 > >> entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > > > Add wakeup to make sure the wait for completion will be completed. > > > > --- a/fs/io_uring.c > > +++ b/fs/io_uring.c > > @@ -6903,6 +6903,7 @@ static int io_sqe_files_unregister(struc > > static void io_sq_thread_stop(struct io_ring_ctx *ctx) > > { > > if (ctx->sqo_thread) { > > + wake_up_process(ctx->sqo_thread); > > wait_for_completion(&ctx->sq_thread_comp); > > /* > > * The park is a bit of a work-around, without it we get > > Yeah this looks reasonable, if the thread is attempted stopped if it > was created de-activated and never started. > > Needs a comment to that effect. Care to add that and send it as a > properly formatted patch (with commit message, etc)? What happened with this fix? The bug is marked as fixed with commit "io_uring: fix task hung in io_uring_setup": https://syzkaller.appspot.com/bug?id=a2b6779df9f5006318875364e0f18cc3af14fa60 but this commit cannot be found in any tree. ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: INFO: task hung in io_uring_setup 2020-10-30 10:01 ` Dmitry Vyukov @ 2020-10-30 14:01 ` Jens Axboe 2020-10-30 18:34 ` Dmitry Vyukov 0 siblings, 1 reply; 5+ messages in thread From: Jens Axboe @ 2020-10-30 14:01 UTC (permalink / raw) To: Dmitry Vyukov Cc: Hillf Danton, syzbot, io-uring, Kees Cook, linux-fsdevel, LKML, sgarzare, syzkaller-bugs, Al Viro On 10/30/20 4:01 AM, Dmitry Vyukov wrote: > On Thu, Sep 3, 2020 at 1:44 PM Jens Axboe <[email protected]> wrote: >> >> On 9/3/20 5:15 AM, Hillf Danton wrote: >>> >>> Thu, 03 Sep 2020 01:38:15 -0700 >>>> syzbot found the following issue on: >>>> >>>> HEAD commit: 4442749a Add linux-next specific files for 20200902 >>>> git tree: linux-next >>>> console output: https://syzkaller.appspot.com/x/log.txt?x=12f9e915900000 >>>> kernel config: https://syzkaller.appspot.com/x/.config?x=39134fcec6c78e33 >>>> dashboard link: https://syzkaller.appspot.com/bug?extid=107dd59d1efcaf3ffca4 >>>> compiler: gcc (GCC) 10.1.0-syz 20200507 >>>> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11594671900000 >>>> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=111ca835900000 >>>> >>>> The issue was bisected to: >>>> >>>> commit dfe127799f8e663c7e3e48b5275ca538b278177b >>>> Author: Stefano Garzarella <[email protected]> >>>> Date: Thu Aug 27 14:58:31 2020 +0000 >>>> >>>> io_uring: allow disabling rings during the creation >>>> >>>> bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=11bc66c1900000 >>>> final oops: https://syzkaller.appspot.com/x/report.txt?x=13bc66c1900000 >>>> console output: https://syzkaller.appspot.com/x/log.txt?x=15bc66c1900000 >>>> >>>> IMPORTANT: if you fix the issue, please add the following tag to the commit: >>>> Reported-by: [email protected] >>>> Fixes: dfe127799f8e ("io_uring: allow disabling rings during the creation") >>>> >>>> INFO: task syz-executor047:6853 blocked for more than 143 seconds. >>>> Not tainted 5.9.0-rc3-next-20200902-syzkaller #0 >>>> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. >>>> task:syz-executor047 state:D stack:28104 pid: 6853 ppid: 6847 flags:0x00004000 >>>> Call Trace: >>>> context_switch kernel/sched/core.c:3777 [inline] >>>> __schedule+0xea9/0x2230 kernel/sched/core.c:4526 >>>> schedule+0xd0/0x2a0 kernel/sched/core.c:4601 >>>> schedule_timeout+0x1d8/0x250 kernel/time/timer.c:1855 >>>> do_wait_for_common kernel/sched/completion.c:85 [inline] >>>> __wait_for_common kernel/sched/completion.c:106 [inline] >>>> wait_for_common kernel/sched/completion.c:117 [inline] >>>> wait_for_completion+0x163/0x260 kernel/sched/completion.c:138 >>>> io_sq_thread_stop fs/io_uring.c:6906 [inline] >>>> io_finish_async fs/io_uring.c:6920 [inline] >>>> io_sq_offload_create fs/io_uring.c:7595 [inline] >>>> io_uring_create fs/io_uring.c:8671 [inline] >>>> io_uring_setup+0x1495/0x29a0 fs/io_uring.c:8744 >>>> do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 >>>> entry_SYSCALL_64_after_hwframe+0x44/0xa9 >>>> RIP: 0033:0x440299 >>>> Code: Bad RIP value. >>>> RSP: 002b:00007ffc57cff668 EFLAGS: 00000246 ORIG_RAX: 00000000000001a9 >>>> RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440299 >>>> RDX: 0000000000400b40 RSI: 0000000020000100 RDI: 0000000000003ffe >>>> RBP: 00000000006ca018 R08: 0000000000000000 R09: 0000000000000000 >>>> R10: 00000000ffffffff R11: 0000000000000246 R12: 0000000000401aa0 >>>> R13: 0000000000401b30 R14: 0000000000000000 R15: 0000000000000000 >>>> INFO: task io_uring-sq:6854 blocked for more than 143 seconds. >>>> Not tainted 5.9.0-rc3-next-20200902-syzkaller #0 >>>> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. >>>> task:io_uring-sq state:D stack:31200 pid: 6854 ppid: 2 flags:0x00004000 >>>> Call Trace: >>>> context_switch kernel/sched/core.c:3777 [inline] >>>> __schedule+0xea9/0x2230 kernel/sched/core.c:4526 >>>> schedule+0xd0/0x2a0 kernel/sched/core.c:4601 >>>> schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4660 >>>> kthread+0x2ac/0x4a0 kernel/kthread.c:285 >>>> ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 >>>> >>>> Showing all locks held in the system: >>>> 1 lock held by khungtaskd/1174: >>>> #0: ffffffff89c67980 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5829 >>>> 3 locks held by in:imklog/6525: >>>> #0: ffff8880a3de2df0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:930 >>>> #1: ffff8880907d8968 (&mm->mmap_lock#2){++++}-{3:3}, at: rq_lock kernel/sched/sched.h:1292 [inline] >>>> #1: ffff8880907d8968 (&mm->mmap_lock#2){++++}-{3:3}, at: ttwu_queue kernel/sched/core.c:2698 [inline] >>>> #1: ffff8880907d8968 (&mm->mmap_lock#2){++++}-{3:3}, at: try_to_wake_up+0x52b/0x12b0 kernel/sched/core.c:2978 >>>> #2: ffff8880ae620ec8 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x2fb/0x400 kernel/sched/psi.c:833 >>>> >>>> ============================================= >>>> >>>> NMI backtrace for cpu 1 >>>> CPU: 1 PID: 1174 Comm: khungtaskd Not tainted 5.9.0-rc3-next-20200902-syzkaller #0 >>>> 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+0x198/0x1fd lib/dump_stack.c:118 >>>> nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105 >>>> nmi_trigger_cpumask_backtrace+0x1b3/0x223 lib/nmi_backtrace.c:62 >>>> trigger_all_cpu_backtrace include/linux/nmi.h:147 [inline] >>>> check_hung_uninterruptible_tasks kernel/hung_task.c:253 [inline] >>>> watchdog+0xd89/0xf30 kernel/hung_task.c:339 >>>> kthread+0x3b5/0x4a0 kernel/kthread.c:292 >>>> ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 >>>> Sending NMI from CPU 1 to CPUs 0: >>>> NMI backtrace for cpu 0 >>>> CPU: 0 PID: 3901 Comm: systemd-journal Not tainted 5.9.0-rc3-next-20200902-syzkaller #0 >>>> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 >>>> RIP: 0010:unwind_next_frame+0x139a/0x1f90 arch/x86/kernel/unwind_orc.c:607 >>>> Code: 49 39 47 28 0f 85 3e f0 ff ff 80 3d df 2c 84 09 00 0f 85 31 f0 ff ff e9 06 18 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 14 24 <48> c1 ea 03 80 3c 02 00 0f 85 02 08 00 00 49 8d 7f 08 49 8b 6f 38 >>>> RSP: 0018:ffffc900040475f8 EFLAGS: 00000246 >>>> RAX: dffffc0000000000 RBX: 1ffff92000808ec7 RCX: 1ffff92000808ee2 >>>> RDX: ffffc90004047708 RSI: ffffc90004047aa8 RDI: ffffc90004047aa8 >>>> RBP: 0000000000000001 R08: ffffffff8b32a670 R09: 0000000000000001 >>>> R10: 000000000007201e R11: 0000000000000001 R12: ffffc90004047ac8 >>>> R13: ffffc90004047705 R14: ffffc90004047720 R15: ffffc900040476d0 >>>> FS: 00007efc659ac8c0(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 >>>> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >>>> CR2: 00007efc62d51000 CR3: 0000000093d6a000 CR4: 00000000001506f0 >>>> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 >>>> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 >>>> Call Trace: >>>> arch_stack_walk+0x81/0xf0 arch/x86/kernel/stacktrace.c:25 >>>> stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:123 >>>> kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 >>>> kasan_set_track mm/kasan/common.c:56 [inline] >>>> __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461 >>>> slab_post_alloc_hook mm/slab.h:517 [inline] >>>> slab_alloc mm/slab.c:3312 [inline] >>>> kmem_cache_alloc+0x13a/0x3a0 mm/slab.c:3482 >>>> kmem_cache_zalloc include/linux/slab.h:656 [inline] >>>> __alloc_file+0x21/0x350 fs/file_table.c:101 >>>> alloc_empty_file+0x6d/0x170 fs/file_table.c:151 >>>> path_openat+0xe3/0x2730 fs/namei.c:3354 >>>> do_filp_open+0x17e/0x3c0 fs/namei.c:3395 >>>> do_sys_openat2+0x16d/0x420 fs/open.c:1168 >>>> do_sys_open fs/open.c:1184 [inline] >>>> __do_sys_open fs/open.c:1192 [inline] >>>> __se_sys_open fs/open.c:1188 [inline] >>>> __x64_sys_open+0x119/0x1c0 fs/open.c:1188 >>>> do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 >>>> entry_SYSCALL_64_after_hwframe+0x44/0xa9 >>> >>> Add wakeup to make sure the wait for completion will be completed. >>> >>> --- a/fs/io_uring.c >>> +++ b/fs/io_uring.c >>> @@ -6903,6 +6903,7 @@ static int io_sqe_files_unregister(struc >>> static void io_sq_thread_stop(struct io_ring_ctx *ctx) >>> { >>> if (ctx->sqo_thread) { >>> + wake_up_process(ctx->sqo_thread); >>> wait_for_completion(&ctx->sq_thread_comp); >>> /* >>> * The park is a bit of a work-around, without it we get >> >> Yeah this looks reasonable, if the thread is attempted stopped if it >> was created de-activated and never started. >> >> Needs a comment to that effect. Care to add that and send it as a >> properly formatted patch (with commit message, etc)? > > What happened with this fix? > The bug is marked as fixed with commit "io_uring: fix task hung in > io_uring_setup": > https://syzkaller.appspot.com/bug?id=a2b6779df9f5006318875364e0f18cc3af14fa60 > but this commit cannot be found in any tree. I don't think Hillf ever sent in that patch, but it did get corrected as part of: commit 7e84e1c7566a1df470a9e1f49d3db2ce311261a4 Author: Stefano Garzarella <[email protected]> Date: Thu Aug 27 16:58:31 2020 +0200 io_uring: allow disabling rings during the creation which should have been done as a separate patch. I'll queue one up for -stable. -- Jens Axboe ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: INFO: task hung in io_uring_setup 2020-10-30 14:01 ` Jens Axboe @ 2020-10-30 18:34 ` Dmitry Vyukov 0 siblings, 0 replies; 5+ messages in thread From: Dmitry Vyukov @ 2020-10-30 18:34 UTC (permalink / raw) To: Jens Axboe Cc: Hillf Danton, syzbot, io-uring, Kees Cook, linux-fsdevel, LKML, Stefano Garzarella, syzkaller-bugs, Al Viro On Fri, Oct 30, 2020 at 3:01 PM Jens Axboe <[email protected]> wrote: > > On 10/30/20 4:01 AM, Dmitry Vyukov wrote: > > On Thu, Sep 3, 2020 at 1:44 PM Jens Axboe <[email protected]> wrote: > >> > >> On 9/3/20 5:15 AM, Hillf Danton wrote: > >>> > >>> Thu, 03 Sep 2020 01:38:15 -0700 > >>>> syzbot found the following issue on: > >>>> > >>>> HEAD commit: 4442749a Add linux-next specific files for 20200902 > >>>> git tree: linux-next > >>>> console output: https://syzkaller.appspot.com/x/log.txt?x=12f9e915900000 > >>>> kernel config: https://syzkaller.appspot.com/x/.config?x=39134fcec6c78e33 > >>>> dashboard link: https://syzkaller.appspot.com/bug?extid=107dd59d1efcaf3ffca4 > >>>> compiler: gcc (GCC) 10.1.0-syz 20200507 > >>>> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11594671900000 > >>>> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=111ca835900000 > >>>> > >>>> The issue was bisected to: > >>>> > >>>> commit dfe127799f8e663c7e3e48b5275ca538b278177b > >>>> Author: Stefano Garzarella <[email protected]> > >>>> Date: Thu Aug 27 14:58:31 2020 +0000 > >>>> > >>>> io_uring: allow disabling rings during the creation > >>>> > >>>> bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=11bc66c1900000 > >>>> final oops: https://syzkaller.appspot.com/x/report.txt?x=13bc66c1900000 > >>>> console output: https://syzkaller.appspot.com/x/log.txt?x=15bc66c1900000 > >>>> > >>>> IMPORTANT: if you fix the issue, please add the following tag to the commit: > >>>> Reported-by: [email protected] > >>>> Fixes: dfe127799f8e ("io_uring: allow disabling rings during the creation") > >>>> > >>>> INFO: task syz-executor047:6853 blocked for more than 143 seconds. > >>>> Not tainted 5.9.0-rc3-next-20200902-syzkaller #0 > >>>> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > >>>> task:syz-executor047 state:D stack:28104 pid: 6853 ppid: 6847 flags:0x00004000 > >>>> Call Trace: > >>>> context_switch kernel/sched/core.c:3777 [inline] > >>>> __schedule+0xea9/0x2230 kernel/sched/core.c:4526 > >>>> schedule+0xd0/0x2a0 kernel/sched/core.c:4601 > >>>> schedule_timeout+0x1d8/0x250 kernel/time/timer.c:1855 > >>>> do_wait_for_common kernel/sched/completion.c:85 [inline] > >>>> __wait_for_common kernel/sched/completion.c:106 [inline] > >>>> wait_for_common kernel/sched/completion.c:117 [inline] > >>>> wait_for_completion+0x163/0x260 kernel/sched/completion.c:138 > >>>> io_sq_thread_stop fs/io_uring.c:6906 [inline] > >>>> io_finish_async fs/io_uring.c:6920 [inline] > >>>> io_sq_offload_create fs/io_uring.c:7595 [inline] > >>>> io_uring_create fs/io_uring.c:8671 [inline] > >>>> io_uring_setup+0x1495/0x29a0 fs/io_uring.c:8744 > >>>> do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 > >>>> entry_SYSCALL_64_after_hwframe+0x44/0xa9 > >>>> RIP: 0033:0x440299 > >>>> Code: Bad RIP value. > >>>> RSP: 002b:00007ffc57cff668 EFLAGS: 00000246 ORIG_RAX: 00000000000001a9 > >>>> RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440299 > >>>> RDX: 0000000000400b40 RSI: 0000000020000100 RDI: 0000000000003ffe > >>>> RBP: 00000000006ca018 R08: 0000000000000000 R09: 0000000000000000 > >>>> R10: 00000000ffffffff R11: 0000000000000246 R12: 0000000000401aa0 > >>>> R13: 0000000000401b30 R14: 0000000000000000 R15: 0000000000000000 > >>>> INFO: task io_uring-sq:6854 blocked for more than 143 seconds. > >>>> Not tainted 5.9.0-rc3-next-20200902-syzkaller #0 > >>>> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > >>>> task:io_uring-sq state:D stack:31200 pid: 6854 ppid: 2 flags:0x00004000 > >>>> Call Trace: > >>>> context_switch kernel/sched/core.c:3777 [inline] > >>>> __schedule+0xea9/0x2230 kernel/sched/core.c:4526 > >>>> schedule+0xd0/0x2a0 kernel/sched/core.c:4601 > >>>> schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4660 > >>>> kthread+0x2ac/0x4a0 kernel/kthread.c:285 > >>>> ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 > >>>> > >>>> Showing all locks held in the system: > >>>> 1 lock held by khungtaskd/1174: > >>>> #0: ffffffff89c67980 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5829 > >>>> 3 locks held by in:imklog/6525: > >>>> #0: ffff8880a3de2df0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:930 > >>>> #1: ffff8880907d8968 (&mm->mmap_lock#2){++++}-{3:3}, at: rq_lock kernel/sched/sched.h:1292 [inline] > >>>> #1: ffff8880907d8968 (&mm->mmap_lock#2){++++}-{3:3}, at: ttwu_queue kernel/sched/core.c:2698 [inline] > >>>> #1: ffff8880907d8968 (&mm->mmap_lock#2){++++}-{3:3}, at: try_to_wake_up+0x52b/0x12b0 kernel/sched/core.c:2978 > >>>> #2: ffff8880ae620ec8 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x2fb/0x400 kernel/sched/psi.c:833 > >>>> > >>>> ============================================= > >>>> > >>>> NMI backtrace for cpu 1 > >>>> CPU: 1 PID: 1174 Comm: khungtaskd Not tainted 5.9.0-rc3-next-20200902-syzkaller #0 > >>>> 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+0x198/0x1fd lib/dump_stack.c:118 > >>>> nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105 > >>>> nmi_trigger_cpumask_backtrace+0x1b3/0x223 lib/nmi_backtrace.c:62 > >>>> trigger_all_cpu_backtrace include/linux/nmi.h:147 [inline] > >>>> check_hung_uninterruptible_tasks kernel/hung_task.c:253 [inline] > >>>> watchdog+0xd89/0xf30 kernel/hung_task.c:339 > >>>> kthread+0x3b5/0x4a0 kernel/kthread.c:292 > >>>> ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 > >>>> Sending NMI from CPU 1 to CPUs 0: > >>>> NMI backtrace for cpu 0 > >>>> CPU: 0 PID: 3901 Comm: systemd-journal Not tainted 5.9.0-rc3-next-20200902-syzkaller #0 > >>>> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > >>>> RIP: 0010:unwind_next_frame+0x139a/0x1f90 arch/x86/kernel/unwind_orc.c:607 > >>>> Code: 49 39 47 28 0f 85 3e f0 ff ff 80 3d df 2c 84 09 00 0f 85 31 f0 ff ff e9 06 18 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 14 24 <48> c1 ea 03 80 3c 02 00 0f 85 02 08 00 00 49 8d 7f 08 49 8b 6f 38 > >>>> RSP: 0018:ffffc900040475f8 EFLAGS: 00000246 > >>>> RAX: dffffc0000000000 RBX: 1ffff92000808ec7 RCX: 1ffff92000808ee2 > >>>> RDX: ffffc90004047708 RSI: ffffc90004047aa8 RDI: ffffc90004047aa8 > >>>> RBP: 0000000000000001 R08: ffffffff8b32a670 R09: 0000000000000001 > >>>> R10: 000000000007201e R11: 0000000000000001 R12: ffffc90004047ac8 > >>>> R13: ffffc90004047705 R14: ffffc90004047720 R15: ffffc900040476d0 > >>>> FS: 00007efc659ac8c0(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 > >>>> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > >>>> CR2: 00007efc62d51000 CR3: 0000000093d6a000 CR4: 00000000001506f0 > >>>> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > >>>> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > >>>> Call Trace: > >>>> arch_stack_walk+0x81/0xf0 arch/x86/kernel/stacktrace.c:25 > >>>> stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:123 > >>>> kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 > >>>> kasan_set_track mm/kasan/common.c:56 [inline] > >>>> __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461 > >>>> slab_post_alloc_hook mm/slab.h:517 [inline] > >>>> slab_alloc mm/slab.c:3312 [inline] > >>>> kmem_cache_alloc+0x13a/0x3a0 mm/slab.c:3482 > >>>> kmem_cache_zalloc include/linux/slab.h:656 [inline] > >>>> __alloc_file+0x21/0x350 fs/file_table.c:101 > >>>> alloc_empty_file+0x6d/0x170 fs/file_table.c:151 > >>>> path_openat+0xe3/0x2730 fs/namei.c:3354 > >>>> do_filp_open+0x17e/0x3c0 fs/namei.c:3395 > >>>> do_sys_openat2+0x16d/0x420 fs/open.c:1168 > >>>> do_sys_open fs/open.c:1184 [inline] > >>>> __do_sys_open fs/open.c:1192 [inline] > >>>> __se_sys_open fs/open.c:1188 [inline] > >>>> __x64_sys_open+0x119/0x1c0 fs/open.c:1188 > >>>> do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 > >>>> entry_SYSCALL_64_after_hwframe+0x44/0xa9 > >>> > >>> Add wakeup to make sure the wait for completion will be completed. > >>> > >>> --- a/fs/io_uring.c > >>> +++ b/fs/io_uring.c > >>> @@ -6903,6 +6903,7 @@ static int io_sqe_files_unregister(struc > >>> static void io_sq_thread_stop(struct io_ring_ctx *ctx) > >>> { > >>> if (ctx->sqo_thread) { > >>> + wake_up_process(ctx->sqo_thread); > >>> wait_for_completion(&ctx->sq_thread_comp); > >>> /* > >>> * The park is a bit of a work-around, without it we get > >> > >> Yeah this looks reasonable, if the thread is attempted stopped if it > >> was created de-activated and never started. > >> > >> Needs a comment to that effect. Care to add that and send it as a > >> properly formatted patch (with commit message, etc)? > > > > What happened with this fix? > > The bug is marked as fixed with commit "io_uring: fix task hung in > > io_uring_setup": > > https://syzkaller.appspot.com/bug?id=a2b6779df9f5006318875364e0f18cc3af14fa60 > > but this commit cannot be found in any tree. > > I don't think Hillf ever sent in that patch, but it did get corrected as > part of: > > commit 7e84e1c7566a1df470a9e1f49d3db2ce311261a4 > Author: Stefano Garzarella <[email protected]> > Date: Thu Aug 27 16:58:31 2020 +0200 > > io_uring: allow disabling rings during the creation > > which should have been done as a separate patch. I'll queue one up for > -stable. Thanks. Let's tell syzbot that this is not an issue anymore: #syz fix: io_uring: allow disabling rings during the creation ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2020-10-30 18:34 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
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2020-09-03 8:38 INFO: task hung in io_uring_setup syzbot
[not found] ` <[email protected]>
2020-09-03 11:44 ` Jens Axboe
2020-10-30 10:01 ` Dmitry Vyukov
2020-10-30 14:01 ` Jens Axboe
2020-10-30 18:34 ` Dmitry Vyukov
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