INFO: task syz-executor:8882 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:21832 pid:8882  tgid:8882  ppid:1      task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 v9fs_evict_inode+0x170/0x320
 evict+0x504/0x9c0
 __dentry_kill+0x209/0x660
 dput+0x19f/0x2b0
 shrink_dcache_for_umount+0xa0/0x170
 generic_shutdown_super+0x67/0x2c0
 kill_anon_super+0x3b/0x70
 v9fs_kill_super+0x4c/0x90
 deactivate_locked_super+0xbc/0x130
 cleanup_mnt+0x425/0x4c0
 task_work_run+0x1d4/0x260
 exit_to_user_mode_loop+0xec/0x110
 do_syscall_64+0x2bd/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc09698ff17
RSP: 002b:00007ffdbcaea5c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fc096a11c05 RCX: 00007fc09698ff17
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffdbcaea680
RBP: 00007ffdbcaea680 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffdbcaeb710
R13: 00007fc096a11c05 R14: 0000000000031d2b R15: 00007ffdbcaeb750
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e139ea0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5673:
 #0: ffff888104d890a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900028fb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
3 locks held by kworker/u9:6/8335:
1 lock held by syz-executor/8882:
 #0: ffff88803176c0e0 (&type->s_umount_key#113){++++}-{4:4}, at: deactivate_super+0xa9/0xe0
2 locks held by dhcpcd/13825:
 #0: ffff888123ad7408 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: sock_close+0x9b/0x240
 #1: ffffffff8e13f938 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730

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

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: 13825 Comm: dhcpcd 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:lock_acquire+0xcd/0x360
Code: 0f 85 eb 00 00 00 65 48 8b 04 25 08 40 a0 92 83 b8 ec 0a 00 00 00 0f 85 d5 00 00 00 48 c7 44 24 30 00 00 00 00 9c 8f 44 24 30 <4c> 89 74 24 10 4d 89 fe 4c 8b 7c 24 30 fa 48 c7 c7 ba a4 9c 8d e8
RSP: 0018:ffffc90002c673d8 EFLAGS: 00000246
RAX: ffff88810b935640 RBX: 0000000000000000 RCX: 991a686d2b917900
RDX: 0000000000000000 RSI: ffffffff8172c1b2 RDI: 1ffffffff1c273d4
RBP: ffffffff8172c195 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc90002c67598 R11: ffffffff81ac3910 R12: 0000000000000002
R13: ffffffff8e139ea0 R14: 0000000000000000 R15: 0000000000000000
FS:  00007feac3cf7740(0000) GS:ffff8880b861c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000563ff1206680 CR3: 000000012d1f6000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 unwind_next_frame+0xc2/0x2390
 arch_stack_walk+0x11c/0x150
 stack_trace_save+0x9c/0xe0
 kasan_save_stack+0x3e/0x60
 kasan_record_aux_stack+0xbd/0xd0
 call_rcu+0x157/0x9c0
 evict+0x847/0x9c0
 __dentry_kill+0x209/0x660
 dput+0x19f/0x2b0
 __fput+0x68e/0xa70
 task_work_run+0x1d4/0x260
 do_exit+0x6b5/0x2300
 do_group_exit+0x21c/0x2d0
 __x64_sys_exit_group+0x3f/0x40
 x64_sys_call+0x21f7/0x2200
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7feac3da7a90
Code: Unable to access opcode bytes at 0x7feac3da7a66.
RSP: 002b:00007ffcd40c8e98 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007feac3cf76c0 RCX: 00007feac3da7a90
RDX: 00000000000000e7 RSI: 000000000000003c RDI: 0000000000000001
RBP: 00007ffcd40c8f18 R08: 0000000000000007 R09: a8598f76a808a9b1
R10: 0000000000000120 R11: 0000000000000202 R12: 0000000000000001
R13: 00007ffcd40c94e8 R14: 0000000000000003 R15: 0000000000000000
 </TASK>
