[syzbot] INFO: task hung in io_wq_put_and_exit (3)

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syzbot

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Mar 23, 2022, 1:52:29 PM3/23/22
to asml.s...@gmail.com, ax...@kernel.dk, io-u...@vger.kernel.org, linux-...@vger.kernel.org, syzkall...@googlegroups.com
Hello,

syzbot found the following issue on:

HEAD commit: b47d5a4f6b8d Merge tag 'audit-pr-20220321' of git://git.ke..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=15e065dd700000
kernel config: https://syzkaller.appspot.com/x/.config?x=63af44f0631a5c3a
dashboard link: https://syzkaller.appspot.com/bug?extid=adb05ed2853417be49ce
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16d673db700000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14627e25700000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+adb05e...@syzkaller.appspotmail.com

INFO: task syz-executor123:3634 blocked for more than 143 seconds.
Tainted: G W 5.17.0-syzkaller-01442-gb47d5a4f6b8d #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor123 state:D stack:28160 pid: 3634 ppid: 3633 flags:0x00000004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:4995 [inline]
__schedule+0xa94/0x4910 kernel/sched/core.c:6304
schedule+0xd2/0x1f0 kernel/sched/core.c:6376
schedule_timeout+0x1db/0x2a0 kernel/time/timer.c:1857
do_wait_for_common kernel/sched/completion.c:85 [inline]
__wait_for_common+0x2af/0x360 kernel/sched/completion.c:106
io_wq_exit_workers fs/io-wq.c:1264 [inline]
io_wq_put_and_exit+0x4d6/0xe40 fs/io-wq.c:1299
io_uring_clean_tctx fs/io_uring.c:10512 [inline]
io_uring_cancel_generic+0x60b/0x695 fs/io_uring.c:10582
io_uring_files_cancel include/linux/io_uring.h:18 [inline]
do_exit+0x4f9/0x29d0 kernel/exit.c:761
do_group_exit+0xd2/0x2f0 kernel/exit.c:936
__do_sys_exit_group kernel/exit.c:947 [inline]
__se_sys_exit_group kernel/exit.c:945 [inline]
__x64_sys_exit_group+0x3a/0x50 kernel/exit.c:945
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fa616b7dbd9
RSP: 002b:00007ffd0ba19358 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007fa616bf2350 RCX: 00007fa616b7dbd9
RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffffffffffc0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa616bf2350
R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000001
</TASK>
INFO: lockdep is turned off.
NMI backtrace for cpu 1
CPU: 1 PID: 28 Comm: khungtaskd Tainted: G W 5.17.0-syzkaller-01442-gb47d5a4f6b8d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x1e6/0x230 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
watchdog+0xc1d/0xf50 kernel/hung_task.c:369
kthread+0x2e9/0x3a0 kernel/kthread.c:377
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 3635 Comm: iou-wrk-3634 Tainted: G W 5.17.0-syzkaller-01442-gb47d5a4f6b8d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__ldsem_down_read_nested+0x32/0x850 drivers/tty/tty_ldsem.c:297
Code: ff df 41 57 41 56 41 89 f6 41 55 41 54 49 89 fc 55 4d 8d 7c 24 70 48 89 d5 53 48 81 ec c8 00 00 00 48 c7 44 24 28 b3 8a b5 41 <4c> 8d 6c 24 28 48 c7 44 24 30 c8 4d 47 8b 49 c1 ed 03 48 c7 44 24
RSP: 0018:ffffc9000115f718 EFLAGS: 00000296
RAX: dffffc0000000000 RBX: ffff88814a2bd000 RCX: 0000000000000000
RDX: 7fffffffffffffff RSI: 0000000000000000 RDI: ffff88814a2bd028
RBP: 7fffffffffffffff R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff843a08bd R11: 0000000000000000 R12: ffff88814a2bd028
R13: 0000000000000000 R14: 0000000000000000 R15: ffff88814a2bd098
FS: 000055555665d300(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055555665d2c0 CR3: 0000000072dfd000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:244
tty_read+0x1a2/0x5d0 drivers/tty/tty_io.c:928
call_read_iter include/linux/fs.h:2068 [inline]
io_iter_do_read fs/io_uring.c:3789 [inline]
io_read+0x330/0x12a0 fs/io_uring.c:3859
io_issue_sqe+0x813/0x8390 fs/io_uring.c:7172
io_wq_submit_work+0x1ed/0x590 fs/io_uring.c:7340
io_worker_handle_work+0xad6/0x1b30 fs/io-wq.c:595
io_wqe_worker+0x606/0xd40 fs/io-wq.c:642
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.426 msecs
----------------
Code disassembly (best guess), 1 bytes skipped:
0: df 41 57 filds 0x57(%rcx)
3: 41 56 push %r14
5: 41 89 f6 mov %esi,%r14d
8: 41 55 push %r13
a: 41 54 push %r12
c: 49 89 fc mov %rdi,%r12
f: 55 push %rbp
10: 4d 8d 7c 24 70 lea 0x70(%r12),%r15
15: 48 89 d5 mov %rdx,%rbp
18: 53 push %rbx
19: 48 81 ec c8 00 00 00 sub $0xc8,%rsp
20: 48 c7 44 24 28 b3 8a movq $0x41b58ab3,0x28(%rsp)
27: b5 41
* 29: 4c 8d 6c 24 28 lea 0x28(%rsp),%r13 <-- trapping instruction
2e: 48 c7 44 24 30 c8 4d movq $0xffffffff8b474dc8,0x30(%rsp)
35: 47 8b
37: 49 c1 ed 03 shr $0x3,%r13
3b: 48 rex.W
3c: c7 .byte 0xc7
3d: 44 rex.R
3e: 24 .byte 0x24


---
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Pavel Begunkov

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Mar 23, 2022, 3:38:07 PM3/23/22
to syzbot, ax...@kernel.dk, io-u...@vger.kernel.org, linux-...@vger.kernel.org, syzkall...@googlegroups.com
On 3/23/22 17:52, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: b47d5a4f6b8d Merge tag 'audit-pr-20220321' of git://git.ke..
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=15e065dd700000
> kernel config: https://syzkaller.appspot.com/x/.config?x=63af44f0631a5c3a
> dashboard link: https://syzkaller.appspot.com/bug?extid=adb05ed2853417be49ce
> compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16d673db700000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14627e25700000
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+adb05e...@syzkaller.appspotmail.com

#syz test: git://git.kernel.dk/linux-block for-5.18/io_uring


--
Pavel Begunkov

syzbot

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Mar 23, 2022, 7:17:15 PM3/23/22
to asml.s...@gmail.com, ax...@kernel.dk, io-u...@vger.kernel.org, linux-...@vger.kernel.org, syzkall...@googlegroups.com
Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+adb05e...@syzkaller.appspotmail.com

Tested on:

commit: 8a3e8ee5 io_uring: add flag for disabling provided buf..
git tree: git://git.kernel.dk/linux-block for-5.18/io_uring
kernel config: https://syzkaller.appspot.com/x/.config?x=3172c0bf8614827
dashboard link: https://syzkaller.appspot.com/bug?extid=adb05ed2853417be49ce
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

Note: no patches were applied.
Note: testing is done by a robot and is best-effort only.

syzbot

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Aug 20, 2023, 4:26:35 AM8/20/23
to syzkall...@googlegroups.com
Auto-closing this bug as obsolete.
No recent activity, existing reproducers are no longer triggering the issue.
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