INFO: task syz.7.1209:15041 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.1209      state:D stack:25512 pid:15041 tgid:15040 ppid:13450  task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17d9/0x56c0
 schedule+0x164/0x2b0
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_read_slowpath+0x6ba/0x920
 down_read+0x9c/0x330
 super_lock+0x2d6/0x3d0
 __iterate_supers+0x120/0x240
 __ia32_sys_sync+0xa0/0x120
 do_syscall_64+0x174/0x580
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe9cdb9ce59
RSP: 002b:00007fe9cea86028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007fe9cde15fa0 RCX: 00007fe9cdb9ce59
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fe9cde15fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe9cde16038 R14: 00007fe9cde15fa0 R15: 00007ffe2f7fc5b8
 </TASK>
INFO: task syz.7.1209:15054 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.1209      state:D stack:28168 pid:15054 tgid:15040 ppid:13450  task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17d9/0x56c0
 schedule+0x164/0x2b0
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_read_slowpath+0x6ba/0x920
 down_read+0x9c/0x330
 super_lock+0x2d6/0x3d0
 __iterate_supers+0x120/0x240
 __ia32_sys_sync+0xa0/0x120
 do_syscall_64+0x174/0x580
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe9cdb9ce59
RSP: 002b:00007fe9cea65028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007fe9cde16090 RCX: 00007fe9cdb9ce59
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fe9cde16090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe9cde16128 R14: 00007fe9cde16090 R15: 00007ffe2f7fc5b8
 </TASK>
INFO: task syz.6.1211:15052 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.1211      state:D stack:25512 pid:15052 tgid:15051 ppid:14271  task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17d9/0x56c0
 schedule+0x164/0x2b0
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_read_slowpath+0x6ba/0x920
 down_read+0x9c/0x330
 super_lock+0x2d6/0x3d0
 user_get_super+0xc8/0x120
 __se_sys_quotactl+0x538/0x9a0
 do_syscall_64+0x174/0x580
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f87c319ce59
RSP: 002b:00007f87c3f7f028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007f87c3415fa0 RCX: 00007f87c319ce59
RDX: 0000000000000000 RSI: 0000200000000000 RDI: ffffffff80000501
RBP: 00007f87c3232e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f87c3416038 R14: 00007f87c3415fa0 R15: 00007ffeeedd21d8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e959c20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
3 locks held by kworker/0:3/994:
 #0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
 #1: ffffc90006c27c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
 #2: ffff8881046f6250 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x1fd/0x3b0
2 locks held by getty/5438:
 #0: ffff8881604dd0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900034732e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360
3 locks held by kworker/0:6/5692:
4 locks held by syz-executor/9596:
1 lock held by syz.7.1209/15041:
 #0: ffff8881127720d8 (&type->s_umount_key#62){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.7.1209/15054:
 #0: ffff8881127720d8 (&type->s_umount_key#62){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.6.1211/15052:
 #0: ffff8881127720d8 (&type->s_umount_key#62){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.9.1281/15831:
 #0: ffff8881127720d8 (&type->s_umount_key#62){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
3 locks held by syz-executor/16513:
3 locks held by kworker/0:7/16746:
1 lock held by syz.7.1475/17587:
 #0: ffff8881127720d8 (&type->s_umount_key#62){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.6.1507/17814:
 #0: ffff88816cab8bb8 (&ima_iint_mutex_key[depth]){+.+.}-{4:4}, at: ima_file_free+0x18a/0x5d0
1 lock held by syz.6.1507/17815:
1 lock held by syz.6.1507/17827:
 #0: ffff8881127720d8 (&type->s_umount_key#62){++++}-{4:4}, at: super_lock+0x289/0x3d0

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

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+0xe8/0x150
 nmi_cpu_backtrace+0x274/0x2d0
 nmi_trigger_cpumask_backtrace+0x17a/0x380
 sys_info+0x135/0x170
 watchdog+0xfd7/0x1030
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 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: 16746 Comm: kworker/0:7 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_power_efficient gc_worker
RIP: 0010:lock_release+0x15/0x3c0
Code: 0f 1f 44 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 30 49 89 f5 <49> 89 fe 65 48 8b 05 40 ec 9d 11 48 89 44 24 28 0f 1f 44 00 00 65
RSP: 0018:ffffc90006bd7938 EFLAGS: 00000282
RAX: ffffffff89d6d7c6 RBX: dffffc0000000000 RCX: ffff888115528000
RDX: 0000000000000000 RSI: ffffffff89d6ca24 RDI: ffffffff8e959c20
RBP: ffffc90006bd7af0 R08: ffffffff9032fcf7 R09: 1ffffffff2065f9e
R10: dffffc0000000000 R11: fffffbfff2065f9f R12: ffff88810b67d818
R13: ffffffff89d6ca24 R14: 0000000000000001 R15: 0000000000047a23
FS:  0000000000000000(0000) GS:ffff88818dc1d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbf783ea2f8 CR3: 00000001be368000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 gc_worker+0x1084/0x1890
 process_scheduled_works+0xa8e/0x14e0
 worker_thread+0xa47/0xfb0
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
