INFO: task syz.3.8832:28727 blocked for more than 143 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.8832      state:D stack:27592 pid:28727 tgid:28726 ppid:7154   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17b4/0x5680
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7f7/0x1550
 sync_bdevs+0x27e/0x470
 __ia32_sys_sync+0xc5/0x120
 do_syscall_64+0x15f/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7efe39d9cdd9
RSP: 002b:00007efe3ab78028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007efe3a015fa0 RCX: 00007efe39d9cdd9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007efe3a015fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007efe3a016038 R14: 00007efe3a015fa0 R15: 00007fff68ecb358
 </TASK>

Showing all locks held in the system:
1 lock held by rcu_exp_gp_kthr/18:
 #0: ffff88823c63aea0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x31/0x150
2 locks held by kworker/u10:0/27:
 #0: ffff88816a1e8940 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc90000a27c40 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
1 lock held by khungtaskd/35:
 #0: ffffffff8e95cda0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5438:
 #0: ffff8881775960a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000346b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0
1 lock held by udevd/9623:
 #0: ffff88816d758350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30
1 lock held by syz.3.8832/28727:
 #0: ffff88816d758350 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x27e/0x470
5 locks held by syz.9.10407/587:
 #0: ffffffff8fe3ec08 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8fe3ea40 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
 #2: ffffffff8fdcf7c0 (rtnl_mutex){+.+.}-{4:4}, at: ieee80211_unregister_hw+0x55/0x2c0
 #3: ffff888103bb0780 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: ieee80211_remove_interfaces+0x132/0x6c0
 #4: ffffffff8e9630a8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770
2 locks held by syz.0.10409/590:
 #0: ffffffff8fe3ec08 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8fe3ea40 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 35 Comm: khungtaskd Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
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+0xfd3/0x1030
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 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: 3 Comm: pool_workqueue_ Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:zap_class+0xcf/0x340
Code: 49 81 fc 00 00 08 00 0f 84 a4 01 00 00 4e 8b 2c e5 e0 a3 fc 93 4d 85 ed 0f 94 c0 49 83 c5 f8 0f 94 c1 08 c1 75 d7 45 8b 75 00 <41> f6 c6 fc 0f 84 e1 00 00 00 41 c1 ee 08 4a 8d 1c 75 b0 a3 41 93
RSP: 0018:ffffc90000087c50 EFLAGS: 00000046
RAX: 00000000000b6d00 RBX: ffffffff93587f90 RCX: 00000000000b6d00
RDX: ffffffff93fca3d8 RSI: 0000000000000002 RDI: 00000000000fb52d
RBP: ffffffff9440a850 R08: ffffffff81af1878 R09: ffffffff8e95cda0
R10: dffffc0000000000 R11: fffffbfff20614df R12: 000000000005c740
R13: ffffffff94490e70 R14: 000000000117c010 R15: 0000000000001292
FS:  0000000000000000(0000) GS:ffff8882a9293000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055a6226fbf00 CR3: 00000000272c4000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 lockdep_unregister_key+0x1c3/0x350
 pwq_release_workfn+0x6d1/0x8c0
 kthread_worker_fn+0x4ee/0xb20
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
