INFO: task syz.0.1423:9955 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.1423      state:D stack:27992 pid:9955  tgid:9954  ppid:5860   task_flags:0x400040 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7e6/0x1350
 bdev_open+0xe0/0xd30
 blkdev_open+0x457/0x600
 do_dentry_open+0x953/0x13f0
 vfs_open+0x3b/0x340
 path_openat+0x2ee5/0x3830
 do_filp_open+0x1fa/0x410
 do_sys_openat2+0x121/0x1c0
 __x64_sys_openat+0x138/0x170
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff42c58d510
RSP: 002b:00007ff42d35cb70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000020040 RCX: 00007ff42c58d510
RDX: 0000000000020040 RSI: 00007ff42d35cc10 RDI: 00000000ffffff9c
RBP: 00007ff42d35cc10 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd
R13: 00007ff42c7d6038 R14: 00007ff42c7d5fa0 R15: 00007ffd6c241388
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5675:
 #0: ffff8881086ff0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900029032f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
1 lock held by udevd/5997:
 #0: ffff88810997e358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30
1 lock held by syz.0.1423/9955:
 #0: ffff88810997e358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30
2 locks held by kworker/u9:6/12120:
 #0: ffff88801d394948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc900034efbc0 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 34 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250
 nmi_cpu_backtrace+0x39e/0x3d0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 watchdog+0xf93/0xfe0
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 ret_from_fork_asm+0x1a/0x30
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 83 Comm: kworker/u9:2 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Workqueue:  0x0 (events_unbound)
RIP: 0010:lock_is_held_type+0xed/0x190
Code: c7 b0 b3 00 8e 4c 89 fe e8 b0 79 85 f9 eb cb 31 db eb 1c 83 fd ff 74 12 31 c0 f6 43 22 03 0f 95 c0 31 db 39 c5 0f 94 c3 eb 05 <bb> 01 00 00 00 48 c7 c7 1f 98 ba 8d e8 92 16 00 00 b8 ff ff ff ff
RSP: 0018:ffffc90001bff670 EFLAGS: 00000046
RAX: 0000000000000001 RBX: ffff88801c3727b0 RCX: 99fc33e4b0d73700
RDX: 0000000000000000 RSI: ffff888136639f98 RDI: ffff88801c3727b0
RBP: 00000000ffffffff R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff5200037fec8 R12: 0000000000000046
R13: ffff88801c371cc0 R14: ffff888136639f98 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8881a3c15000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe3a0bb6fc8 CR3: 000000010eaf8000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 update_rq_clock+0x8f/0x5b0
 sched_balance_update_blocked_averages+0x20a/0x1580
 sched_balance_newidle+0x46d/0x1030
 pick_next_task_fair+0x40/0xba0
 __pick_next_task+0xe4/0x450
 __schedule+0x7a4/0x4cc0
 schedule+0x165/0x360
 worker_thread+0xa82/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 ret_from_fork_asm+0x1a/0x30
 </TASK>
