INFO: task kworker/u4:0:8 blocked for more than 143 seconds.
      Not tainted 5.11.0-rc2-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:0    state:D stack:24088 pid:    8 ppid:     2 flags:0x00004000
Workqueue: events_unbound io_ring_exit_work
Call Trace:
 context_switch kernel/sched/core.c:4313 [inline]
 __schedule+0x90c/0x21a0 kernel/sched/core.c:5064
 schedule+0xcf/0x270 kernel/sched/core.c:5143
 schedule_timeout+0x1d8/0x250 kernel/time/timer.c:1854
 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
 kthread_park+0x122/0x1b0 kernel/kthread.c:557
 io_sq_thread_park fs/io_uring.c:7375 [inline]
 io_sq_thread_park fs/io_uring.c:7369 [inline]
 io_sq_thread_stop+0xfe/0x570 fs/io_uring.c:7393
 io_finish_async fs/io_uring.c:7411 [inline]
 io_ring_ctx_free fs/io_uring.c:8576 [inline]
 io_ring_exit_work+0xac/0x730 fs/io_uring.c:8668
 process_one_work+0x98d/0x15f0 kernel/workqueue.c:2275
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421
 kthread+0x3b1/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

Showing all locks held in the system:
3 locks held by kworker/u4:0/8:
 #0: ffff888010071138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: ffff888010071138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline]
 #0: ffff888010071138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline]
 #0: ffff888010071138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline]
 #0: ffff888010071138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline]
 #0: ffff888010071138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x871/0x15f0 kernel/workqueue.c:2246
 #1: ffffc90000cefda8 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x8a5/0x15f0 kernel/workqueue.c:2250
 #2: ffff888018b27070 (&sqd->lock){+.+.}-{3:3}, at: io_sq_thread_park fs/io_uring.c:7374 [inline]
 #2: ffff888018b27070 (&sqd->lock){+.+.}-{3:3}, at: io_sq_thread_park fs/io_uring.c:7369 [inline]
 #2: ffff888018b27070 (&sqd->lock){+.+.}-{3:3}, at: io_sq_thread_stop+0xd6/0x570 fs/io_uring.c:7393
1 lock held by khungtaskd/1645:
 #0: ffffffff8b363860 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6254
1 lock held by in:imklog/8164:
 #0: ffff8880228b3bb0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:947
4 locks held by syz-executor.4/8494:
1 lock held by systemd-udevd/4852:
1 lock held by syz-executor.1/5198:

=============================================

NMI backtrace for cpu 1
CPU: 1 PID: 1645 Comm: khungtaskd Not tainted 5.11.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x107/0x163 lib/dump_stack.c:120
 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105
 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:209 [inline]
 watchdog+0xd43/0xfa0 kernel/hung_task.c:294
 kthread+0x3b1/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4887 Comm: systemd-journal Not tainted 5.11.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0033:0x55a6b9e6fad0
Code: ff 85 c0 5a 59 0f 88 1e ff ff ff 48 8b 7b 50 48 c7 c6 9c ff ff ff e8 ef 37 ff ff e9 6e ff ff ff e8 85 39 ff ff 0f 1f 44 00 00 <41> 57 41 56 41 55 41 54 55 53 48 81 ec 88 28 00 00 64 48 8b 04 25
RSP: 002b:00007ffeb36293f8 EFLAGS: 00000206
RAX: 00007f8ff73ec7fc RBX: 00007ffeb3629410 RCX: 00007ffeb36295b0
RDX: 0000000000000001 RSI: 0000000000000009 RDI: 00007ffeb36295b0
RBP: 00007ffeb3629408 R08: 0000000000000008 R09: 000055a6bb24e7d8
R10: 000055a6bb24e7a0 R11: 0000000000000206 R12: 000055a6bb24e7a0
R13: 00007ffeb3629508 R14: 000055a6b9e73958 R15: 0005b86779c30749
FS:  00007f8ff77488c0 GS:  0000000000000000