INFO: task kworker/u4:0:8 blocked for more than 143 seconds.
      Not tainted 5.11.0-rc5-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:0    state:D stack:24456 pid:    8 ppid:     2 flags:0x00004000
Workqueue: events_unbound io_ring_exit_work
Call Trace:
 context_switch kernel/sched/core.c:4327 [inline]
 __schedule+0x999/0xe70 kernel/sched/core.c:5078
 schedule+0x14b/0x200 kernel/sched/core.c:5157
 schedule_timeout+0x43/0x250 kernel/time/timer.c:1854
 do_wait_for_common+0x266/0x3a0 kernel/sched/completion.c:85
 __wait_for_common kernel/sched/completion.c:106 [inline]
 wait_for_common kernel/sched/completion.c:117 [inline]
 wait_for_completion+0x43/0x50 kernel/sched/completion.c:138
 kthread_park+0x10d/0x1c0 kernel/kthread.c:582
 io_sq_thread_park fs/io_uring.c:7469 [inline]
 io_sq_thread_stop fs/io_uring.c:7487 [inline]
 io_finish_async+0xd7/0x460 fs/io_uring.c:7505
 io_ring_ctx_free fs/io_uring.c:8670 [inline]
 io_ring_exit_work+0x55/0x4c0 fs/io_uring.c:8763
 process_one_work+0x789/0xfc0 kernel/workqueue.c:2275
 worker_thread+0xac1/0x1300 kernel/workqueue.c:2421
 kthread+0x39a/0x3c0 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: ffff888010469138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x6f4/0xfc0 kernel/workqueue.c:2248
 #1: ffffc90000cd7d78 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x733/0xfc0 kernel/workqueue.c:2250
 #2: ffff88802b958070 (&sqd->lock){+.+.}-{3:3}, at: io_sq_thread_park fs/io_uring.c:7468 [inline]
 #2: ffff88802b958070 (&sqd->lock){+.+.}-{3:3}, at: io_sq_thread_stop fs/io_uring.c:7487 [inline]
 #2: ffff88802b958070 (&sqd->lock){+.+.}-{3:3}, at: io_finish_async+0xbb/0x460 fs/io_uring.c:7505
2 locks held by kworker/u4:1/24:
1 lock held by khungtaskd/1649:
 #0: ffffffff8bd11740 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 arch/x86/pci/mmconfig_64.c:151
1 lock held by systemd-udevd/4888:
1 lock held by in:imklog/8384:
 #0: ffff88801ad4fc70 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x24e/0x2f0 fs/file.c:947
1 lock held by syz-executor.1/8471:
 #0: ffff888147494d88 (&xt[i].mutex){+.+.}-{3:3}, at: xt_find_target+0x77/0x230 net/netfilter/x_tables.c:234
2 locks held by syz-executor.3/8475:
 #0: ffff888147494d88 (&xt[i].mutex){+.+.}-{3:3}, at: xt_find_table_lock+0x37/0x410 net/netfilter/x_tables.c:1206
 #1: ffffffff8bd15ae8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
 #1: ffffffff8bd15ae8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x1e8/0x600 kernel/rcu/tree_exp.h:836
2 locks held by syz-executor.5/8485:
 #0: ffff888147494458 (&xt[i].mutex){+.+.}-{3:3}, at: xt_find_table_lock+0x37/0x410 net/netfilter/x_tables.c:1206
 #1: ffffffff8bd15ae8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline]
 #1: ffffffff8bd15ae8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2b5/0x600 kernel/rcu/tree_exp.h:836
2 locks held by kworker/u4:3/15359:
2 locks held by kworker/0:8/16497:
 #0: ffff88801047c538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x6f4/0xfc0 kernel/workqueue.c:2248
 #1: ffffc90016247d78 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x733/0xfc0 kernel/workqueue.c:2250
1 lock held by syz-executor.4/5306:
 #0: ffff888147494d88 (&xt[i].mutex){+.+.}-{3:3}, at: xt_find_match+0x77/0x230 net/netfilter/x_tables.c:185
1 lock held by syz-executor.2/5324:
 #0: ffff888147494d88 (&xt[i].mutex){+.+.}-{3:3}, at: xt_find_match+0x77/0x230 net/netfilter/x_tables.c:185

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

NMI backtrace for cpu 1
CPU: 1 PID: 1649 Comm: khungtaskd Not tainted 5.11.0-rc5-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+0x137/0x1be lib/dump_stack.c:120
 nmi_cpu_backtrace+0x16c/0x190 lib/nmi_backtrace.c:105
 nmi_trigger_cpumask_backtrace+0x191/0x2f0 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+0xce9/0xd30 kernel/hung_task.c:294
 kthread+0x39a/0x3c0 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: 8457 Comm: syz-fuzzer Not tainted 5.11.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x0/0xa0 kernel/kcov.c:285
Code: 54 f9 08 48 c1 e0 03 48 83 c8 18 48 89 34 01 4c 89 44 f9 18 49 ff c2 4c 89 11 c3 0f 1f 44 00 00 66 2e 0f 1f 84 00 00 00 00 00 <4c> 8b 04 24 65 48 8b 14 25 80 ef 01 00 65 8b 05 68 24 8a 7e a9 00
RSP: 0018:ffffc9000168fc78 EFLAGS: 00000046
RAX: cd51bf3ba4bda500 RBX: ffffffff8148a359 RCX: ffff88801da19bc0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: dffffc0000000000 R09: ffffed1003b43379
R10: ffffed1003b43379 R11: 0000000000000000 R12: ffff88801da1b1e0
R13: ffff88801da19bc0 R14: ffffffff812b9355 R15: dffffc0000000000
FS:  000000c0002a4790(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb223035f90 CR3: 0000000014665000 CR4: 00000000001526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 trace_hardirqs_off+0x24/0x70 kernel/trace/trace_preemptirq.c:78
 __local_bh_enable_ip+0x99/0x170 kernel/softirq.c:178
 fpregs_unlock arch/x86/include/asm/fpu/api.h:66 [inline]
 __fpu__restore_sig+0x7af/0xdf0 arch/x86/kernel/fpu/signal.c:369
 restore_sigcontext+0x5fa/0x6a0 arch/x86/kernel/signal.c:139
 __do_sys_rt_sigreturn+0x10c/0x1a0 arch/x86/kernel/signal.c:653
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x41f0b4
Code: c9 48 85 c9 0f 84 0f 01 00 00 48 85 c9 0f 84 f8 00 00 00 48 89 0c 24 48 89 5c 24 08 e8 c5 05 00 00 48 8b 44 24 58 48 8b 48 18 <48> 81 f9 d0 07 00 00 0f 8c bb 00 00 00 48 8d 1d 18 d1 6c 01 f0 48
RSP: 002b:000000c00003bf38 EFLAGS: 00000216
RAX: 000000c00001fe98 RBX: 00007fb22c579d97 RCX: 00000000000001b8
RDX: 0000000000000080 RSI: 0000000000000003 RDI: 0000000000000080
RBP: 000000c00003bf80 R08: 00007fb22c726fff R09: 000000c010a5b280
R10: 000000c00001fe98 R11: 0000000000000080 R12: 00000000000000fa
R13: 000000c000001500 R14: 000000c000048120 R15: ffffffffffffffff