INFO: task syz.6.529:10770 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.529       state:D stack:25304 pid:10770 tgid:10769 ppid:10397  task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x14ef/0x4fb0
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_read_slowpath+0x61e/0x920
 down_read+0x99/0x2e0
 super_lock+0x2d6/0x3d0
 user_get_super+0xc8/0x120
 __se_sys_quotactl+0x516/0x990
 do_syscall_64+0xe2/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd0bc59acb9
RSP: 002b:00007fd0bd539028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007fd0bc815fa0 RCX: 00007fd0bc59acb9
RDX: 0000000000000000 RSI: 00002000000000c0 RDI: ffffffff80000801
RBP: 00007fd0bc608bf7 R08: 0000000000000000 R09: 0000000000000000
R10: 0000200000000380 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd0bc816038 R14: 00007fd0bc815fa0 R15: 00007ffc7e81d0e8
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/u8:0/12:
 #0: ffff88817414b148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0
 #1: ffffc90000117bc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0
 #2: ffffffff8f714e88 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x11e/0x14c0
6 locks held by kworker/u8:1/13:
 #0: ffff888100ef7948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0
 #1: ffffc90000127bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0
 #2: ffffffff8f707ab0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xfe/0x7b0
 #3: ffffffff8f714e88 (rtnl_mutex){+.+.}-{4:4}, at: ieee80211_unregister_hw+0x55/0x2c0
 #4: ffff888022918788 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: cfg80211_netdev_notifier_call+0x1a4/0x13c0
 #5: ffffffff8e3476b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770
3 locks held by kworker/u9:0/26:
 #0: ffff888100089948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0
 #1: ffffc90000a17bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0
 #2: ffffffff8f714e88 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60
1 lock held by khungtaskd/35:
 #0: ffffffff8e341b60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
1 lock held by dhcpcd/5575:
 #0: ffffffff8f714e88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0
2 locks held by getty/5656:
 #0: ffff888113bf80a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000355e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0
3 locks held by syz-executor/7715:
3 locks held by kworker/0:6/7768:
 #0: ffff888100075948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0
 #1: ffffc90004427bc0 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0
 #2: ffff88810bacf240 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x202/0x3d0
3 locks held by kworker/1:10/9136:
 #0: ffff888100075948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0
 #1: ffffc90003c87bc0 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0
 #2: ffff8881b61fe240 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x202/0x3d0
1 lock held by syz.6.529/10770:
 #0: ffff8881693ca0e0 (&type->s_umount_key#51){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.6.795/13748:
 #0: ffff8881693ca0e0 (&type->s_umount_key#51){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
4 locks held by syz-executor/14408:
 #0: ffff8881764d6420 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x227/0xb90
 #1: ffff88816f620088 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1de/0x540
 #2: ffff88810b2f23c8 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x231/0x540
 #3: ffffffff8efa00e8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x13c/0x710
1 lock held by syz-executor/14457:
 #0: ffffffff8f714e88 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x404/0x1ad0
7 locks held by syz-executor/14502:
 #0: ffff8881764d6420 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x227/0xb90
 #1: ffff888114927888 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1de/0x540
 #2: ffff88810b2f24b8 (kn->active#48){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x231/0x540
 #3: ffffffff8efa00e8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd7/0x370
 #4: ffff8881b876f0e8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x800
 #5: ffff8881b876e250 (&devlink->lock_key#28){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160
 #6: ffffffff8e347580 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580

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

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+0xe8/0x150
 nmi_cpu_backtrace+0x274/0x2d0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 sys_info+0x135/0x170
 watchdog+0xf90/0xfe0
 kthread+0x726/0x8b0
 ret_from_fork+0x51b/0xa40
 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: 7715 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:do_raw_spin_unlock+0xfd/0x230
Code: 06 ff ff ff ff 42 0f b6 44 25 00 84 c0 0f 85 29 01 00 00 41 c7 07 ff ff ff ff 48 c7 c0 78 c7 1a 8e 48 c1 e8 03 42 80 3c 20 00 <74> 0c 48 c7 c7 78 c7 1a 8e e8 25 c3 89 00 48 83 3d 95 04 7b 0c 00
RSP: 0018:ffffc9000a42f6c8 EFLAGS: 00000246
RAX: 1ffffffff1c358ef RBX: ffff8881bbe8da80 RCX: 0000000000000001
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff8881bbe8da80
RBP: 1ffff110377d1b51 R08: ffff8881bbe8da83 R09: 1ffff110377d1b50
R10: dffffc0000000000 R11: ffffed10377d1b51 R12: dffffc0000000000
R13: 1ffff110377d1b52 R14: ffff8881bbe8da90 R15: ffff8881bbe8da88
FS:  000055555557b500(0000) GS:ffff8882a9a0b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055ab3c537598 CR3: 000000011482a000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 _raw_spin_unlock+0x1e/0x50
 igrab+0x13d/0x1e0
 f2fs_write_checkpoint+0xb5a/0x2490
 kill_f2fs_super+0x308/0x710
 deactivate_locked_super+0xbc/0x130
 cleanup_mnt+0x437/0x4d0
 task_work_run+0x1d9/0x270
 do_exit+0x69b/0x2310
 do_group_exit+0x21b/0x2d0
 __x64_sys_exit_group+0x3f/0x40
 x64_sys_call+0x2210/0x2210
 do_syscall_64+0xe2/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6c1fb9acb9
Code: Unable to access opcode bytes at 0x7f6c1fb9ac8f.
RSP: 002b:00007fff4a86a9c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f6c1fc047c0 RCX: 00007f6c1fb9acb9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000010 R08: 0000000000000000 R09: 00007f6c1fc0471f
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff4a86bc80
R13: 00007f6c1fc0471f R14: 000055555557b4e8 R15: 00007fff4a86cd50
 </TASK>
