INFO: task syz.9.2100:14084 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.9.2100      state:D stack:24456 pid:14084 tgid:14078 ppid:12784  task_flags:0x400140 flags:0x00004006
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7e6/0x1350
 sync_bdevs+0x1ac/0x340
 ksys_sync+0xb9/0x150
 __ia32_sys_sync+0xe/0x20
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4c8d18ebe9
RSP: 002b:00007f4c8dfe6038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f4c8d3c6180 RCX: 00007f4c8d18ebe9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f4c8d3c6180 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4c8d3c6218 R14: 00007f4c8d3c6180 R15: 00007ffee48506b8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e139f20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5670:
 #0: ffff8880285700a0 (&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
2 locks held by kworker/u8:2/5864:
 #0: ffff88804b039f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140
 #1: ffff88804b024008 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880
3 locks held by kworker/0:5/5902:
 #0: ffff88801b7af148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc900041bfbc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff888109a11198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a20
1 lock held by syz-executor/11617:
1 lock held by udevd/11703:
 #0: ffff888020e5a358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30
1 lock held by syz.9.2100/14084:
 #0: ffff888020e5a358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x1ac/0x340
1 lock held by syz.3.2486/15368:
 #0: ffff888020e5a358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x1ac/0x340
3 locks held by syz.4.2701/16615:

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

NMI backtrace for cpu 1
CPU: 1 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+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 14721 Comm: kworker/u9:5 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: events_unbound nsim_dev_trap_report_work
RIP: 0010:stack_depot_save_flags+0x86/0x860
Code: 8d 34 12 42 8d 2c d5 7b 71 f5 75 83 fe 04 72 6f 89 e8 89 e9 4c 89 f2 03 0a 03 42 04 03 6a 08 89 ef c1 c7 04 29 e9 31 cf 01 c5 <29> f8 41 89 f8 41 c1 c0 06 41 31 c0 01 ef 45 89 c1 41 c1 c1 08 44
RSP: 0018:ffffc9000407f5d8 EFLAGS: 00000296
RAX: 000000009792e11b RBX: 0000000000000000 RCX: 00000000811dfe54
RDX: ffffc9000407f658 RSI: 0000000000000012 RDI: 00000000a5b2e536
RBP: 00000000b9ddd2d1 R08: 0000000077377c7e R09: 00000000fccf05ee
R10: 000000000000000c R11: ffffffff81ac3aa0 R12: ffff88801a442140
R13: 0000000000000000 R14: ffffc9000407f640 R15: ffffc9000407f640
FS:  0000000000000000(0000) GS:ffff8880b8618000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f605c5ff000 CR3: 000000002954a000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 kasan_save_track+0x4f/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x5b/0x80
 kfree+0x18e/0x440
 skb_release_data+0x62d/0x7c0
 consume_skb+0x9e/0xf0
 nsim_dev_trap_report_work+0x7cf/0xb80
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
