INFO: task iou-sqp-15142:15144 blocked for more than 143 seconds.
      Not tainted 5.12.0-rc7-next-20210415-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:iou-sqp-15142   state:D stack:29232 pid:15144 ppid:  8479 flags:0x00004004
Call Trace:
 context_switch kernel/sched/core.c:4329 [inline]
 __schedule+0x917/0x2170 kernel/sched/core.c:5079
 schedule+0xcf/0x270 kernel/sched/core.c:5158
 __io_uring_cancel+0x285/0x420 fs/io_uring.c:8977
 io_uring_files_cancel include/linux/io_uring.h:16 [inline]
 do_exit+0x299/0x2a70 kernel/exit.c:780
 io_sq_thread+0x60a/0x1340 fs/io_uring.c:6873
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

Showing all locks held in the system:
1 lock held by khungtaskd/1650:
 #0: ffffffff8bf76560 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6333
2 locks held by in:imklog/8134:
 #0: ffff8880138a79f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990
 #1: ffffffff9035faa0 (&meta->lock){..-.}-{2:2}, at: syslog_print+0x20a/0x430 kernel/printk/printk.c:1502

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

NMI backtrace for cpu 0
CPU: 0 PID: 1650 Comm: khungtaskd Not tainted 5.12.0-rc7-next-20210415-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+0x141/0x1d7 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:253 [inline]
 watchdog+0xd3b/0xf50 kernel/hung_task.c:338
 kthread+0x3b1/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 13642 Comm: kworker/1:17 Not tainted 5.12.0-rc7-next-20210415-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events nsim_dev_trap_report_work
RIP: 0010:check_preemption_disabled+0x3f/0x150 lib/smp_processor_id.c:60
Code: 8b 25 4d 38 f0 76 65 8b 1d 9e 92 f0 76 81 e3 ff ff ff 7f 31 ff 89 de 0f 1f 44 00 00 85 db 74 11 0f 1f 44 00 00 44 89 e0 5b 5d <41> 5c 41 5d 41 5e c3 0f 1f 44 00 00 9c 5b 81 e3 00 02 00 00 31 ff
RSP: 0018:ffffc90002737af0 EFLAGS: 00000002
RAX: 0000000000000001 RBX: 0000000000000004 RCX: 0000000000000001
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000
RBP: ffffffff8bf764a0 R08: 0000000000000000 R09: 0000000000000001
R10: ffffffff842ba2ca R11: 0000000000000000 R12: 0000000000000001
R13: ffffffff896ba760 R14: 00000000ffffffff R15: ffff888023b0a6f0
FS:  0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f35ea647000 CR3: 00000000127c6000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 lockdep_recursion_finish kernel/locking/lockdep.c:438 [inline]
 lock_is_held_type+0xd5/0x140 kernel/locking/lockdep.c:5556
 lock_is_held include/linux/lockdep.h:283 [inline]
 rcu_read_lock_sched_held+0x3a/0x70 kernel/rcu/update.c:125
 trace_get_random_bytes include/trace/events/random.h:160 [inline]
 _get_random_bytes+0x540/0x670 drivers/char/random.c:1529
 nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:540 [inline]
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:570 [inline]
 nsim_dev_trap_report_work+0x740/0xbd0 drivers/net/netdevsim/dev.c:611
 process_one_work+0x98d/0x1600 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:294