INFO: task syz.2.583:9390 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.583       state:D stack:16856 pid:9390  tgid:9389  ppid:5851   task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 __closure_sync+0x163/0x220
 bch2_read_iter+0x1034/0x1440
 vfs_read+0x55a/0xa30
 ksys_read+0x145/0x250
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f935e18ec29
RSP: 002b:00007f935f011038 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007f935e3d5fa0 RCX: 00007f935e18ec29
RDX: 0000000000001000 RSI: 0000200000001400 RDI: 0000000000000006
RBP: 00007f935e211e41 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f935e3d6038 R14: 00007f935e3d5fa0 R15: 00007ffd9e220be8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5675:
 #0: ffff88802976f0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900029062f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
1 lock held by syz.2.583/9390:
 #0: ffff88803dff5af8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x247/0x320
3 locks held by syz-executor/11480:
 #0: ffff888120ce40e0 (&type->s_umount_key#56){++++}-{4:4}, at: deactivate_super+0xa9/0xe0
 #1: ffff88812d200278 (&c->state_lock){++++}-{4:4}, at: __bch2_fs_stop+0xf8/0x900
 #2: ffffffff8e13fb78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730
3 locks held by syz.1.1236/12564:
 #0: ffff8880123840f8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x247/0x320
 #1: ffff888042660428 (sb_writers#5){.+.+}-{0:0}, at: vfs_write+0x211/0xb30
 #2: ffff888125af8950 (&sb->s_type->i_mutex_key#13){++++}-{4:4}, at: shmem_file_write_iter+0x7f/0x120
5 locks held by syz.1.1236/12565:
1 lock held by syz.6.1238/12583:

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

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+0x439/0x7d0
 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: 12 Comm: kworker/u8:0 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: bat_events batadv_nc_worker
RIP: 0010:batadv_nc_worker+0x2b5/0x610
Code: f6 e8 af 3f 5f f6 48 8b 44 24 20 42 0f b6 04 20 84 c0 75 1b 49 ff c7 4c 8b 6c 24 10 41 8b 45 00 49 39 c7 73 25 e8 2b d3 77 f6 <e9> ed fd ff ff 48 8b 4c 24 10 80 e1 07 80 c1 03 38 c1 7c d6 48 8b
RSP: 0018:ffffc900000f7a20 EFLAGS: 00000293
RAX: ffffffff8b47da65 RBX: ffff888022b31900 RCX: ffff88801c68d640
RDX: 0000000000000000 RSI: ffffffff8dba9940 RDI: ffff88801c68d640
RBP: fffffffffffffe38 R08: 0000000000000000 R09: ffffffff8b47d882
R10: dffffc0000000000 R11: fffffbfff1f474e7 R12: dffffc0000000000
R13: ffff888022b31910 R14: ffff88811deecd80 R15: 000000000000038f
FS:  0000000000000000(0000) GS:ffff8880b8613000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c258269 CR3: 000000012d288000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 ret_from_fork_asm+0x1a/0x30
 </TASK>
