INFO: task syz-executor:5853 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:5853  tgid:5853  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: 0033:0x7fc75818ff17
RSP: 002b:00007ffe336703e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fc758211c05 RCX: 00007fc75818ff17
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe336704a0
RBP: 00007ffe336704a0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffe33671530
R13: 00007fc758211c05 R14: 000000000003e3de R15: 00007ffe33671570
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5671:
 #0: ffff888022c990a0 (&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 syz-executor/5853:
 #0: ffff88803a4000e0 (&type->s_umount_key#117){++++}-{4:4}, at: deactivate_super+0xa9/0xe0
1 lock held by syz.7.2388/18932:
 #0: ffff88803a4000e0 (&type->s_umount_key#117){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
3 locks held by syz.6.2915/21930:
 #0: ffff88802419e0f8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x247/0x320
 #1: ffff888119552428 (sb_writers#19){.+.+}-{0:0}, at: vfs_writev+0x288/0x960
 #2: ffff888111dca448 (&sb->s_type->i_mutex_key#30){+.+.}-{4:4}, at: fuse_fsync+0x111/0x310

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

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: 5876 Comm: kworker/u8:3 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: bat_events batadv_nc_worker
RIP: 0010:mark_lock+0xd/0x190
Code: 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 41 57 41 56 41 55 41 54 53 8b 46 20 <89> c1 81 e1 00 00 03 00 83 f9 01 bb 09 00 00 00 83 db 00 83 fa 08
RSP: 0018:ffffc90004557808 EFLAGS: 00000046
RAX: 0000000000040783 RBX: ffff888023d09cc0 RCX: 0000000000000000
RDX: 0000000000000002 RSI: ffff888023d0a800 RDI: ffff888023d09cc0
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8b479b87
R10: dffffc0000000000 R11: fffffbfff1f47147 R12: 00000000ffffff05
R13: 0000000000000003 R14: ffff888023d0a800 R15: ffff888023d0a820
FS:  0000000000000000(0000) GS:ffff8880b861b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055558851a5c8 CR3: 000000010e538000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 __lock_acquire+0x9b6/0xd20
 lock_acquire+0x120/0x360
 _raw_spin_lock_bh+0x36/0x50
 batadv_nc_purge_paths+0xe7/0x3b0
 batadv_nc_worker+0x328/0x610
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
