INFO: task kworker/1:1H:96 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:1H    state:D stack:25568 pid:96    tgid:96    ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: kblockd blk_mq_requeue_work
Call Trace:
 <TASK>
 __schedule+0x17b4/0x5680
 schedule+0x164/0x360
 schedule_timeout+0x158/0x2c0
 nbd_queue_rq+0x857/0x1100
 blk_mq_dispatch_rq_list+0xa70/0x1910
 __blk_mq_sched_dispatch_requests+0xdcc/0x1600
 blk_mq_sched_dispatch_requests+0xd7/0x190
 blk_mq_run_hw_queue+0x348/0x4f0
 blk_mq_run_hw_queues+0x26c/0x3f0
 blk_mq_requeue_work+0x71c/0x780
 process_scheduled_works+0xb5d/0x1860
 worker_thread+0xa53/0xfc0
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
4 locks held by kworker/1:1H/96:
 #0: ffff888161eded40 ((wq_completion)kblockd){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc90002837c40 ((work_completion)(&(&q->requeue_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
 #2: ffff888101bac418 (set->srcu){.+.+}-{0:0}, at: blk_mq_run_hw_queue+0x31f/0x4f0
 #3: ffff8881ac84cb78 (&cmd->lock){+.+.}-{4:4}, at: nbd_queue_rq+0xc6/0x1100
2 locks held by getty/5436:
 #0: ffff888100b1d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900034732e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0
1 lock held by udevd/20540:
 #0: ffff888101ff0350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30
3 locks held by syz.1.31354/30976:
3 locks held by syz.1.31354/30977:
 #0: ffffffff9032cfa0 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250
 #1: ffffffff8fdd0300 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x883/0x1bb0
 #2: ffffffff8e962f38 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580
2 locks held by syz.1.31354/30981:
 #0: ffffffff90328918 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250
 #1: ffffffff8fdd0300 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x883/0x1bb0
1 lock held by syz.1.31354/30982:
 #0: ffffffff8fdd0300 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x883/0x1bb0
1 lock held by syz.1.31354/30983:
 #0: ffffffff8fdd0300 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x722/0xbe0

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

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+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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 5046 Comm: klogd 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:security_unix_may_send+0x76/0x270
Code: 62 fd 0f 1f 44 00 00 e8 38 51 62 fd 0f 1f 44 00 00 e8 2e 51 62 fd 0f 1f 44 00 00 e8 24 51 62 fd 0f 1f 44 00 00 e8 1a 51 62 fd <31> c0 5b 41 5e 41 5f 5d e9 3d 29 49 07 cc 4c 89 f7 48 89 de e8 81
RSP: 0018:ffffc900030efab8 EFLAGS: 00000293
RAX: ffffffff84636e56 RBX: ffff88817a820c40 RCX: ffff88817a3ad880
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffc900030ef8ff R09: 0000000000000000
R10: ffffc900030ef870 R11: fffff5200061df20 R12: ffff888111b32c38
R13: 1ffff9200061df7c R14: ffff88810c538640 R15: 0000000000000000
FS:  00007fdb49621380(0000) GS:ffff88818dc87000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f94acfea4c0 CR3: 000000010e6d6000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 unix_dgram_sendmsg+0xaa9/0x18d0
 __sys_sendto+0x672/0x710
 __x64_sys_sendto+0xde/0x100
 do_syscall_64+0x15f/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fdb497839b5
Code: 8b 44 24 08 48 83 c4 28 48 98 c3 48 98 c3 41 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 26 45 31 c9 45 31 c0 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 76 7a 48 8b 15 44 c4 0c 00 f7 d8 64 89 02 48 83
RSP: 002b:00007fff237a2e78 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007fdb497839b5
RDX: 000000000000004c RSI: 00005568461ec3c0 RDI: 0000000000000003
RBP: 00005568461e2910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000004000 R11: 0000000000000246 R12: 0000000000000013
R13: 00007fdb49911212 R14: 00007fff237a2f78 R15: 0000000000000000
 </TASK>
