INFO: task syz.5.327:7729 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.327       state:D
 stack:24136 pid:7729  tgid:7728  ppid:7518   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: 0033:0x7f10baf8eba9
RSP: 002b:00007f10bbee3038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f10bb1d5fa0 RCX: 00007f10baf8eba9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f10bb1d5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f10bb1d6038 R14: 00007f10bb1d5fa0 R15: 00007fff759a9d08
 </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
1 lock held by acpid/5282:
2 locks held by getty/5675:
 #0: ffff88802920a0a0 (&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
2 locks held by syz-executor/5850:
 #0: ffffffff8e88ef08 (bio_slab_lock){+.+.}-{4:4}, at: bioset_exit+0x44a/0x690
 #1: ffffffff8e13fa40 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570
2 locks held by syz-executor/5852:
7 locks held by kworker/1:3/5897:
 #0: ffff8881051b7148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90003b2fbc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff88802457c198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a20
 #3: ffff888115293198 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0xf8/0x950
 #4: ffff8881088e4160 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x800
 #5: ffffffff8efa8328 (input_mutex){+.+.}-{4:4}, at: __input_unregister_device+0x328/0x640
 #6: ffffffff8e13fb78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730
2 locks held by kworker/u8:4/5911:
 #0: ffff888136639f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140
 #1: ffff888136624008 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880
1 lock held by syz.5.327/7729:
 #0: ffff888035c9c0e0 (&type->s_umount_key#65){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
2 locks held by syz.2.917/10405:
 #0: ffff888104d5dc08 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: sock_close+0x9b/0x240
 #1: ffffffff8e13fb78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730

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

NMI backtrace for cpu 0
CPU: 0 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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 9948 Comm: syz-executor 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
RIP: 0010:rcu_is_watching+0x15/0xb0
Code: 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 57 41 56 53 65 ff 05 30 40 fa 10 e8 1b 01 d4 09 <89> c3 83 f8 08 73 65 49 bf 00 00 00 00 00 fc ff df 4c 8d 34 dd 10
RSP: 0018:ffffc90003577978 EFLAGS: 00000286
RAX: 0000000000000001 RBX: 0000000000000001 RCX: 30635bbd292dfb00
RDX: 0000000000000000 RSI: ffffffff8be33e60 RDI: ffffffff8be33e20
RBP: ffffc90003577bd0 R08: 0000000000000000 R09: ffffffff8484fd8a
R10: dffffc0000000000 R11: ffffed1003edb881 R12: dffffc0000000000
R13: ffffffff8484fd8a R14: ffffffff8e13a0e0 R15: ffff8881000120f8
FS:  00005555869bd500(0000) GS:ffff8881a3c15000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32b12ffa CR3: 0000000047ee8000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 lock_release+0x4b/0x3e0
 aa_file_perm+0x448/0x1550
 common_file_perm+0x1a9/0x230
 security_file_permission+0x91/0x290
 rw_verify_area+0xbb/0x4d0
 vfs_write+0x15a/0xb30
 ksys_write+0x145/0x250
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc12d38d65f
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 92 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 4c 93 02 00 48
RSP: 002b:00007ffd38fb0f90 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000000000000006e RCX: 00007fc12d38d65f
RDX: 0000000000000004 RSI: 00007ffd38fb1050 RDI: 00000000000000f8
RBP: 00007ffd38fb0ffc R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000023
R13: 00000000000927c0 R14: 000000000004ef1a R15: 00007ffd38fb1050
 </TASK>
