INFO: task syz.9.1171:13340 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.9.1171      state:D stack:25336 pid:13340 tgid:13339 ppid:7593   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x14bc/0x5000
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_read_slowpath+0x5fd/0x8f0
 down_read+0x99/0x2e0
 super_lock+0x2a9/0x3b0
 __iterate_supers+0x126/0x290
 ksys_sync+0x94/0x150
 __ia32_sys_sync+0xe/0x20
 do_syscall_64+0xfa/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f215018f7c9
RSP: 002b:00007f21510f4038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f21503e5fa0 RCX: 00007f215018f7c9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f21503e5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f21503e6038 R14: 00007f21503e5fa0 R15: 00007ffc61b0fc08
 </TASK>
INFO: task syz.1.1175:13360 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.1175      state:D stack:24856 pid:13360 tgid:13359 ppid:12356  task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x14bc/0x5000
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_read_slowpath+0x5fd/0x8f0
 down_read+0x99/0x2e0
 super_lock+0x2a9/0x3b0
 __iterate_supers+0x126/0x290
 __se_sys_quotactl+0x353/0x950
 do_syscall_64+0xfa/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1c3b38f7c9
RSP: 002b:00007f1c3c30c038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007f1c3b5e5fa0 RCX: 00007f1c3b38f7c9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000101
RBP: 00007f1c3b3f297f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1c3b5e6038 R14: 00007f1c3b5e5fa0 R15: 00007ffc676fc868
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/35:
 #0: ffffffff8df419e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
3 locks held by kworker/u11:0/56:
 #0: ffff8881063d3948 ((wq_completion)hci6){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770
 #1: ffffc9000142fb80 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770
 #2: ffff88811c95cec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1d3/0x400
3 locks held by kworker/0:3/5298:
 #0: ffff888100075948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770
 #1: ffffc900036d7b80 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770
 #2: ffff888117b06240 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x1f7/0x3b0
2 locks held by getty/5658:
 #0: ffff88816b9570a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000356b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x449/0x1460
3 locks held by syz-executor/12403:
1 lock held by syz.9.1171/13340:
 #0: ffff8881b21420e0 (&type->s_umount_key#77){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.1.1175/13360:
 #0: ffff8881b21420e0 (&type->s_umount_key#77){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.4.1188/13650:
 #0: ffff8881b21420e0 (&type->s_umount_key#77){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.0.1195/13748:
 #0: ffff8881b21420e0 (&type->s_umount_key#77){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.5.1202/13778:
 #0: ffff8881b21420e0 (&type->s_umount_key#77){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.2.1203/13853:
 #0: ffff8881b21420e0 (&type->s_umount_key#77){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.3.1206/13989:
 #0: ffff8881b21420e0 (&type->s_umount_key#77){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.8.1209/14089:
 #0: ffff8881b21420e0 (&type->s_umount_key#77){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.6.1211/14169:
 #0: ffff8881b21420e0 (&type->s_umount_key#77){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.9.1212/14216:
 #0: ffff8881b21420e0 (&type->s_umount_key#77){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.9.1212/14217:
 #0: ffff8881b21420e0 (&type->s_umount_key#77){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.9.1212/14218:
 #0: ffff8881b21420e0 (&type->s_umount_key#77){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.7.1214/14248:
 #0: ffff8881b21420e0 (&type->s_umount_key#77){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.1.1220/14283:
 #0: ffff8881b21420e0 (&type->s_umount_key#77){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.4.1224/14323:
 #0: ffff8881b21420e0 (&type->s_umount_key#77){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.0.1226/14347:
 #0: ffff8881b21420e0 (&type->s_umount_key#77){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.5.1239/14417:
 #0: ffff8881b21420e0 (&type->s_umount_key#77){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.3.1245/14467:
 #0: ffff8881b21420e0 (&type->s_umount_key#77){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.2.1246/14472:
 #0: ffff8881b21420e0 (&type->s_umount_key#77){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.8.1253/14526:
 #0: ffff8881b21420e0 (&type->s_umount_key#77){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.9.1257/14584:
 #0: ffff8881b21420e0 (&type->s_umount_key#77){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.6.1263/14599:
 #0: ffff8881b21420e0 (&type->s_umount_key#77){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.7.1266/14640:
 #0: ffff8881b21420e0 (&type->s_umount_key#77){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.1.1270/14681:
 #0: ffff8881b21420e0 (&type->s_umount_key#77){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.4.1277/14727:
 #0: ffff8881b21420e0 (&type->s_umount_key#77){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.0.1279/14757:
 #0: ffff8881b21420e0 (&type->s_umount_key#77){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.0.1279/14758:
 #0: ffff8881b21420e0 (&type->s_umount_key#77){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
8 locks held by syz-executor/14762:
 #0: ffff88817322c420 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x211/0xb30
 #1: ffff8881848a6888 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1de/0x540
 #2: ffff888108ffd4b8 (kn->active#48){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x231/0x540
 #3: ffffffff8eb9d6a8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x360
 #4: ffff888022fc10e8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x800
 #5: ffff888118f91250 (&devlink->lock_key#33){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160
 #6: ffffffff8f30f948 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0xed/0x680
 #7: ffffffff8df47538 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 35 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
 sys_info+0x135/0x170
 watchdog+0xf95/0xfe0
 kthread+0x711/0x8a0
 ret_from_fork+0x599/0xb30
 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: 12403 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:__lock_acquire+0x525/0x2cf0
Code: 00 48 83 c3 28 41 89 c4 49 39 cf 0f 8d c7 00 00 00 49 83 ff 31 0f 83 83 00 00 00 8b 03 25 ff 1f 00 00 48 0f a3 05 7b 96 e7 11 <73> 10 48 69 c0 c8 00 00 00 48 8d 88 b0 13 27 93 eb 32 83 3d 42 26
RSP: 0018:ffffc90005687688 EFLAGS: 00000007
RAX: 0000000000000982 RBX: ffff88816b29a8b8 RCX: 0000000000000002
RDX: 0000000000000004 RSI: 0000000000000005 RDI: 0000000000000000
RBP: ffff88816b29a8c0 R08: ffffffff84145861 R09: ffff888112c30ca0
R10: dffffc0000000000 R11: ffffed1037764041 R12: 0000000000000004
R13: ffff88816b29a8c0 R14: ffff88816b299d40 R15: 0000000000000001
FS:  0000555568ab5500(0000) GS:ffff8882a9e3a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055ee70adae38 CR3: 0000000173a0a000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 lock_acquire+0x117/0x340
 _raw_spin_lock+0x2e/0x40
 f2fs_write_checkpoint+0xa91/0x2430
 kill_f2fs_super+0x2d2/0x6c0
 deactivate_locked_super+0xbc/0x130
 cleanup_mnt+0x425/0x4c0
 task_work_run+0x1d4/0x260
 exit_to_user_mode_loop+0xff/0x4f0
 do_syscall_64+0x2e3/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc6fc790af7
Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffc469d6518 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fc6fc7ee72f RCX: 00007fc6fc790af7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc469d65d0
RBP: 00007ffc469d65d0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffc469d7660
R13: 00007fc6fc7ee72f R14: 000000000005e9f8 R15: 00007ffc469d76a0
 </TASK>
