INFO: task syz.5.1406:17168 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.1406      state:D stack:27720 pid:17168 tgid:17166 ppid:16388  task_flags:0x400140 flags:0x00004004
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/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcde8d8ec29
RSP: 002b:00007fcde9b3e038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007fcde8fd5fa0 RCX: 00007fcde8d8ec29
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fcde8fd5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fcde8fd6038 R14: 00007fcde8fd5fa0 R15: 00007ffc9d666d88
 </TASK>
INFO: task syz.5.1406:17170 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.1406      state:D stack:26664 pid:17170 tgid:17166 ppid:16388  task_flags:0x400040 flags:0x00004004
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/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcde8d8ec29
RSP: 002b:00007fcde6fd5038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007fcde8fd6180 RCX: 00007fcde8d8ec29
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fcde8fd6180 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fcde8fd6218 R14: 00007fcde8fd6180 R15: 00007ffc9d666d88
 </TASK>

Showing all locks held in the system:
1 lock held by rcu_exp_gp_kthr/18:
 #0: ffff888136639fd8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140
1 lock held by khungtaskd/34:
 #0: ffffffff8dd3aca0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
1 lock held by acpid/5257:
 #0: ffffffff8dd40738 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730
1 lock held by udevd/5272:
2 locks held by getty/5651:
 #0: ffff88810e1bd0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900027782f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
4 locks held by kworker/u8:4/5888:
1 lock held by udevd/13434:
 #0: ffff888107ef5358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30
1 lock held by syz.5.1406/17168:
 #0: ffff888107ef5358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x1ac/0x340
1 lock held by syz.5.1406/17170:
 #0: ffff888107ef5358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x1ac/0x340
1 lock held by syz-executor/18151:
 #0: ffffffff8dd40738 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730
2 locks held by syz.0.1633/18742:
 #0: ffff888030f620e0 (&type->s_umount_key#112/1){+.+.}-{4:4}, at: alloc_super+0x204/0x970
 #1: ffff888107ef5358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30
4 locks held by syz.2.1780/19476:
 #0: ffff88801a078ca0 (&mm->mmap_lock){++++}-{4:4}, at: raw_spin_rq_lock_nested+0x2a/0x140
 #1: ffff888136624048 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880
 #2: ffffffff99835458 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0xbb/0x420
 #3: ffffffff8dd3aca0 (rcu_read_lock){....}-{1:3}, at: is_bpf_text_address+0x26/0x2b0

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

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+0x187/0x610
Code: 4b 03 00 00 48 c7 c2 60 81 72 8c e8 83 6c 98 f6 48 89 e8 48 c1 e8 03 42 80 3c 20 00 74 08 48 89 ef e8 3d 11 1e f7 48 8b 6d 00 <48> 85 ed 0f 94 c0 48 81 c5 38 fe ff ff 0f 94 c1 08 c1 74 07 e8 30
RSP: 0018:ffffc900000f7a20 EFLAGS: 00000246
RAX: 1ffff110241b88b8 RBX: 0000000000000001 RCX: ffff88801beed640
RDX: 0000000000000000 RSI: ffffffff8b9e6fc0 RDI: ffffffff8b9e6f80
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8b038522
R10: dffffc0000000000 R11: ffffffff8b038450 R12: dffffc0000000000
R13: ffffffff8b038522 R14: ffff888124614d80 R15: 00000000000000b8
FS:  0000000000000000(0000) GS:ffff8880b8d7e000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055557188b608 CR3: 000000001f592000 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>
