INFO: task syz.7.2322:14410 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.7.2322      state:D stack:24088 pid:14410 tgid:14376 ppid:11786  task_flags:0x400140 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: 0033:0x7f36dc79cdd9
RSP: 002b:00007f36da9f6028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f36dca16180 RCX: 00007f36dc79cdd9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f36dca16180 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f36dca16218 R14: 00007f36dca16180 R15: 00007fffaccdc098
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e95cda0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
3 locks held by kworker/u11:1/4999:
 #0: ffff8881bd0d3940 ((wq_completion)hci3){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc900082efc40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
 #2: ffff8881bb098ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1d3/0x400
2 locks held by getty/5432:
 #0: ffff888114f7c0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000347b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0
1 lock held by udevd/5621:
 #0: ffff88816a770350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30
1 lock held by syz.7.2322/14410:
 #0: ffff88816a770350 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x27e/0x470
1 lock held by syz.8.2613/15344:
 #0: ffff88816a770350 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x27e/0x470
1 lock held by syz.8.2613/15352:
 #0: ffff88816a770350 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x27e/0x470
1 lock held by syz-executor/16428:
2 locks held by syz.4.3097/17052:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 34 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: 17056 Comm: syz.1.3098 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:serial8250_console_write+0x165/0x1ba0
Code: 02 00 00 e8 9d e9 80 fc e9 93 00 00 00 4c 89 ff e8 f0 14 66 06 48 89 44 24 60 48 c7 c0 c0 e4 30 90 48 c1 e8 03 42 0f b6 04 28 <84> c0 0f 85 3a 17 00 00 44 8b 35 ec 29 ec 0a 31 ff 44 89 f6 e8 a2
RSP: 0018:ffffc90003d66aa0 EFLAGS: 00000802
RAX: 0000000000000000 RBX: 0000000000000200 RCX: 0000000000000001
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc90003d66a00
RBP: ffffc90003d66c10 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff520007acd40 R12: 0000000000000000
R13: dffffc0000000000 R14: 0000000000000000 R15: ffffffff9a79f740
FS:  00007f3f0a3db6c0(0000) GS:ffff8882a9290000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3eff21f000 CR3: 000000016e3f6000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 console_flush_all+0x718/0xb20
 console_unlock+0xd1/0x1c0
 vprintk_emit+0x485/0x560
 _printk+0xdd/0x130
 set_capacity_and_notify+0x2c5/0x320
 loop_set_size+0x44/0xb0
 loop_configure+0x9ac/0xdf0
 lo_ioctl+0x447/0x1fb0
 blkdev_ioctl+0x5e3/0x740
 __se_sys_ioctl+0xfc/0x170
 do_syscall_64+0x15f/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3f0959ca6b
Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00
RSP: 002b:00007f3f0a3dadb0 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007f3f0959ca6b
RDX: 0000000000000003 RSI: 0000000000004c00 RDI: 0000000000000004
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 00007f3f0a3daee0 R14: 00007f3f0a3daea0 R15: 00007f3eff200000
 </TASK>
