INFO: task syz.0.1457:17323 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.1457      state:D stack:20776 pid:17323 tgid:17322 ppid:15876  task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_read_slowpath+0x5fd/0x8f0
 down_read+0x98/0x2e0
 super_lock+0x2a9/0x3b0
 __iterate_supers+0x126/0x290
 ksys_sync+0x94/0x150
 __ia32_sys_sync+0xe/0x20
 do_syscall_64+0xfa/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb33b98efc9
RSP: 002b:00007fb33c7cb038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007fb33bbe5fa0 RCX: 00007fb33b98efc9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fb33bbe5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb33bbe6038 R14: 00007fb33bbe5fa0 R15: 00007ffef3f5f2b8
 </TASK>

Showing all locks held in the system:
1 lock held by pool_workqueue_/3:
 #0: ffffffff8df42d78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730
1 lock held by khungtaskd/34:
 #0: ffffffff8df3d2e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
3 locks held by kworker/1:1/47:
2 locks held by getty/5642:
 #0: ffff8881725b80a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900029082f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
3 locks held by syz-executor/12674:
1 lock held by syz.0.1457/17323:
 #0: ffff88816f5440e0 (&type->s_umount_key#62){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
2 locks held by syz.9.1835/20152:
4 locks held by rm/20195:

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

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+0xf60/0xfa0
 kthread+0x711/0x8a0
 ret_from_fork+0x4bc/0x870
 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: 26 Comm: kworker/u9:0 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:__slab_alloc+0x65/0x100
Code: 00 4c 03 2c dd d0 bd 92 8d 41 f7 c7 00 0c 00 00 74 47 4c 89 e7 44 89 fe 89 ea 4c 89 f1 4d 89 e8 44 8b 4c 24 04 e8 ab 00 00 00 <48> 89 c3 bf 01 00 00 00 e8 5e f6 74 ff 65 8b 05 e7 24 53 10 85 c0
RSP: 0018:ffffc90000a17830 EFLAGS: 00000282
RAX: ffff8881abe28000 RBX: 0000000000000001 RCX: 789cc3403160e300
RDX: 0000000000000006 RSI: ffffffff8d70c33c RDI: ffffffff8bbf0760
RBP: 00000000ffffffff R08: ffffffff8f7cd577 R09: 1ffffffff1ef9aae
R10: dffffc0000000000 R11: fffffbfff1ef9aaf R12: ffff888100042140
R13: ffff88823c63e830 R14: ffffffff891f49b2 R15: 0000000000082820
FS:  0000000000000000(0000) GS:ffff8882a9f3e000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdefd736440 CR3: 00000001ae4ba000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 __kmalloc_node_track_caller_noprof+0x5c7/0x800
 kmalloc_reserve+0x136/0x290
 __alloc_skb+0x142/0x2d0
 nsim_dev_trap_report_work+0x29a/0xb80
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x4bc/0x870
 ret_from_fork_asm+0x1a/0x30
 </TASK>
