INFO: task syz-executor:8708 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:18856 pid:8708  tgid:8708  ppid:1      task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 wb_wait_for_completion+0x15f/0x260
 __writeback_inodes_sb_nr+0x1f6/0x250
 sync_filesystem+0xa3/0x230
 generic_shutdown_super+0x6f/0x2c0
 bch2_kill_sb+0x41/0x50
 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: 0033:0x7fa993b8fed7
RSP: 002b:00007fffed3dd368 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fa993c11c05 RCX: 00007fa993b8fed7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fffed3dd420
RBP: 00007fffed3dd420 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fffed3de4b0
R13: 00007fa993c11c05 R14: 000000000003d437 R15: 00007fffed3de4f0
 </TASK>
INFO: task syz.2.486:9710 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.486       state:D stack:22920 pid:9710  tgid:9709  ppid:8873   task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_read_slowpath+0x5fd/0x8f0
 down_read+0x98/0x2e0
 super_lock+0x2a9/0x3b0
 __iterate_supers+0x126/0x290
 ksys_sync+0x94/0x150
 __ia32_sys_sync+0xe/0x20
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4b2bb8eba9
RSP: 002b:00007f4b2cab6038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f4b2bdd5fa0 RCX: 00007f4b2bb8eba9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f4b2bdd5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4b2bdd6038 R14: 00007f4b2bdd5fa0 R15: 00007ffce0c12498
 </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/5677:
 #0: ffff8880223a70a0 (&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
3 locks held by kworker/u8:5/7312:
2 locks held by kworker/u10:6/8327:
 #0: ffff88801b366148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90002f0fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
1 lock held by syz-executor/8708:
 #0: ffff888030d620e0 (&type->s_umount_key#87){++++}-{4:4}, at: deactivate_super+0xa9/0xe0
1 lock held by syz.2.486/9710:
 #0: ffff888030d620e0 (&type->s_umount_key#87){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.3.514/10054:
 #0: ffff888030d620e0 (&type->s_umount_key#87){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.5.533/10295:
 #0: ffff888030d620e0 (&type->s_umount_key#87){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.7.529/10363:
 #0: ffff888030d620e0 (&type->s_umount_key#87){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.6.549/10684:
 #0: ffff888030d620e0 (&type->s_umount_key#87){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.8.563/10906:
 #0: ffff888030d620e0 (&type->s_umount_key#87){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.9.573/10968:
 #0: ffff888030d620e0 (&type->s_umount_key#87){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.1.576/11060:
 #0: ffff888030d620e0 (&type->s_umount_key#87){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.0.587/11108:
 #0: ffff888030d620e0 (&type->s_umount_key#87){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.2.596/11148:
 #0: ffff888030d620e0 (&type->s_umount_key#87){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.4.608/11330:
 #0: ffff888030d620e0 (&type->s_umount_key#87){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.3.637/11442:
 #0: ffff888030d620e0 (&type->s_umount_key#87){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.5.649/11476:
 #0: ffff888030d620e0 (&type->s_umount_key#87){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.7.657/11527:
 #0: ffff888030d620e0 (&type->s_umount_key#87){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.8.668/11618:
 #0: ffff888030d620e0 (&type->s_umount_key#87){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
3 locks held by kworker/0:0H/11644:
 #0: ffff88804b039f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140
 #1: ffff88804b024008 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880
 #2: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: blk_mq_run_work_fn+0x9b/0x300
1 lock held by syz.6.683/11651:
 #0: ffff888030d620e0 (&type->s_umount_key#87){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.9.686/11676:
 #0: ffff888030d620e0 (&type->s_umount_key#87){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.1.691/11711:
 #0: ffff888030d620e0 (&type->s_umount_key#87){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.0.699/11766:
 #0: ffff888030d620e0 (&type->s_umount_key#87){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.2.708/11787:
 #0: ffff888030d620e0 (&type->s_umount_key#87){++++}-{4:4}, at: super_lock+0x2a9/0x3b0

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

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: 53 Comm: kworker/u9:2 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: events_unbound nsim_dev_trap_report_work
RIP: 0010:asm_sysvec_apic_timer_interrupt+0x0/0x20
Code: 56 3c 7a 0a e9 61 06 00 00 90 f3 0f 1e fa 0f 1f 00 fc 6a ff e8 11 05 00 00 48 89 c4 48 89 e7 e8 66 3b 7a 0a e9 41 06 00 00 90 <f3> 0f 1e fa 0f 1f 00 fc 6a ff e8 f1 04 00 00 48 89 c4 48 89 e7 e8
RSP: 0018:ffffc900007bf3f8 EFLAGS: 00000046
RAX: 0000000000000001 RBX: ffffffff8222fbfb RCX: 0000000000000002
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e13a0e0
RBP: dffffc0000000000 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc900007bf558 R11: ffffffff81ac4b00 R12: 1ffff920000f7ea1
R13: ffffc900007bf540 R14: ffffc900007bf508 R15: ffffffff8172d195
FS:  0000000000000000(0000) GS:ffff8880b8615000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd8cefffe00 CR3: 000000007306e000 CR4: 00000000000006f0
Call Trace:
 <TASK>
RIP: 0010:lock_acquire+0x0/0x360
Code: 05 25 43 03 11 a9 00 ff ff 00 0f 95 c0 e9 08 cf df 09 cc 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 55 41 57 41 56 41 55 41 54 53 48 83 ec 60 4d 89 ce 45
RSP: 0018:ffffc900007bf428 EFLAGS: 00000246
 unwind_next_frame+0xc2/0x2390
 arch_stack_walk+0x11c/0x150
 stack_trace_save+0x9c/0xe0
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x5b/0x80
 kfree+0x18e/0x440
 skb_release_data+0x62d/0x7c0
 consume_skb+0x9e/0xf0
 nsim_dev_trap_report_work+0x7cf/0xb80
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 ret_from_fork_asm+0x1a/0x30
 </TASK>
