INFO: task syz.0.4962:19000 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.4962      state:D stack:26280 pid:19000 tgid:18999 ppid:18776  task_flags:0x400140 flags:0x00080002
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/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f08cc38efc9
RSP: 002b:00007f08cd2ec038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f08cc5e5fa0 RCX: 00007f08cc38efc9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f08cc5e5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f08cc5e6038 R14: 00007f08cc5e5fa0 R15: 00007ffdb2d27878
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8df3d620 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5645:
 #0: ffff8881126310a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000357b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
2 locks held by sshd/5739:
1 lock held by udevd/5935:
 #0: ffff8881096fb358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30
3 locks held by kworker/0:13/13893:
 #0: ffff888100075948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc9000908fba0 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff888116af9240 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x1f7/0x3b0
1 lock held by syz.0.4962/19000:
 #0: ffff8881096fb358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x1ac/0x340
1 lock held by syz-executor/20849:
 #0: ffffffff8df430b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730
1 lock held by syz-executor/23731:
 #0: ffffffff8df430b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730
1 lock held by syz.3.6882/23914:
 #0: ffff88812123a058 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140

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

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+0xf60/0xfa0
 kthread+0x711/0x8a0
 ret_from_fork+0x4bc/0x870
 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: 20849 Comm: syz-executor 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
RIP: 0010:unwind_next_frame+0x7cd/0x2390
Code: 0f 84 d3 0d 00 00 48 83 c7 38 e8 0e 28 00 00 49 89 c4 48 8b 34 24 e9 a9 02 00 00 49 8d 5e 40 48 89 d8 48 c1 e8 03 80 3c 28 00 <74> 11 48 89 df e8 29 2c b2 00 48 8b 34 24 48 8b 54 24 08 4c 8b 23
RSP: 0018:ffffc900099cf538 EFLAGS: 00000246
RAX: 1ffff92001339ec9 RBX: ffffc900099cf648 RCX: ffffffff8ffeb954
RDX: ffffffff90b04ffc RSI: ffffffff90b05000 RDI: ffffffff8bbf0800
RBP: dffffc0000000000 R08: 0000000000000001 R09: ffffffff81738d25
R10: ffffc900099cf658 R11: ffffffff81ac2f50 R12: ffffffff90b05001
R13: ffffc900099cf658 R14: ffffc900099cf608 R15: ffffc900099cf640
FS:  000055555b309500(0000) GS:ffff88818eb3d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000561199a1a950 CR3: 0000000118b66000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 arch_stack_walk+0x11c/0x150
 stack_trace_save+0x9c/0xe0
 save_stack+0xf5/0x1f0
 __reset_page_owner+0x71/0x1f0
 __free_frozen_pages+0xbc4/0xd30
 vfree+0x25a/0x400
 kcov_close+0x28/0x50
 __fput+0x44c/0xa70
 task_work_run+0x1d4/0x260
 do_exit+0x6b5/0x2300
 do_group_exit+0x21c/0x2d0
 get_signal+0x1285/0x1340
 arch_do_signal_or_restart+0xa0/0x790
 exit_to_user_mode_loop+0x72/0x130
 do_syscall_64+0x2bd/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb78fd85713
Code: Unable to access opcode bytes at 0x7fb78fd856e9.
RSP: 002b:00007ffe60caf028 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: fffffffffffffff4 RBX: 0000000000000000 RCX: 00007fb78fd85713
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001
R10: 000055555b3097d0 R11: 0000000000000246 R12: 0000000000000000
R13: 00000000000927c0 R14: 00000000000a88ae R15: 00007ffe60caf1c0
 </TASK>
ip6_tunnel: ip6gre2 xmit: Local address not yet configured!
hpet: Lost 1 RTC interrupts
