INFO: task syz-executor:10268 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:21832 pid:10268 tgid:10268 ppid:1      task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 v9fs_evict_inode+0x170/0x320
 evict+0x504/0x9c0
 __dentry_kill+0x209/0x660
 dput+0x19f/0x2b0
 shrink_dcache_for_umount+0xa0/0x170
 generic_shutdown_super+0x67/0x2c0
 kill_anon_super+0x3b/0x70
 v9fs_kill_super+0x4c/0x90
 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: 0033:0x7ff6cf58ff17
RSP: 002b:00007ffcd3112188 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007ff6cf611c05 RCX: 00007ff6cf58ff17
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffcd3112240
RBP: 00007ffcd3112240 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffcd31132d0
R13: 00007ff6cf611c05 R14: 000000000004775b R15: 00007ffcd3113310
 </TASK>

Showing all locks held in the system:
1 lock held by pool_workqueue_/3:
6 locks held by kworker/u8:1/14:
 #0: ffff88801b2f7148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90000117bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f52bdb0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800
 #3: ffffffff8f538c48 (rtnl_mutex){+.+.}-{4:4}, at: ieee80211_unregister_hw+0x55/0x2c0
 #4: ffff88812fd10768 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: cfg80211_netdev_notifier_call+0x1a6/0x1450
 #5: ffffffff8e13f9b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730
1 lock held by khungtaskd/34:
 #0: ffffffff8e139f20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
1 lock held by dhcpcd/5595:
 #0: ffffffff8f538c48 (rtnl_mutex){+.+.}-{4:4}, at: devinet_ioctl+0x323/0x1b50
2 locks held by getty/5684:
 #0: ffff888029af90a0 (&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
2 locks held by kworker/0:4/5894:
 #0: ffff88801a480d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90003d8fbc0 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
1 lock held by syz-executor/10268:
 #0: ffff88810fc8a0e0 (&type->s_umount_key#84){++++}-{4:4}, at: deactivate_super+0xa9/0xe0
1 lock held by syz.4.1126/12356:
 #0: ffff88810fc8a0e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz-executor/13702:
1 lock held by syz.7.1403/13732:
 #0: ffffffff8e13f9b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730

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

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+0x3fc/0x770
 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: 5863 Comm: kworker/u11:3 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: hci1 hci_cmd_work
RIP: 0010:___cache_free+0x5a/0xf0
Code: f6 c1 01 75 79 49 01 c4 66 90 41 0f b6 44 24 33 c1 e0 18 45 31 c0 3d 00 00 00 f5 4d 0f 44 c4 65 48 8b 05 91 35 88 10 49 8b 0f <48> 8b 54 08 08 4c 3b 44 08 10 75 27 48 8b 04 01 41 8b 4f 28 48 89
RSP: 0018:ffffc90003b2f8e8 EFLAGS: 00000246
RAX: ffff8880b8618000 RBX: ffff8880295b1000 RCX: ffffffff92a27630
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff88810f120e00 R08: ffffea0000a56c00 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed1009608001 R12: ffffea0000a56c00
R13: 0000000000000000 R14: ffffffff82232e9c R15: ffff88801a493000
FS:  0000000000000000(0000) GS:ffff8880b8618000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3aa0cd9440 CR3: 000000010f26c000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 qlist_free_all+0x97/0x140
 kasan_quarantine_reduce+0x148/0x160
 __kasan_slab_alloc+0x22/0x80
 kmem_cache_alloc_noprof+0x1c1/0x3c0
 skb_clone+0x212/0x3a0
 hci_cmd_work+0xe1/0x6e0
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
