INFO: task syz.4.29418:14326 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.29418     state:D stack:26536 pid:14326 tgid:14325 ppid:12986  task_flags:0x480140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17db/0x58f0
 schedule+0x164/0x2b0
 blk_mq_freeze_queue_wait+0x101/0x180
 queue_limits_commit_update_frozen+0x55/0xd0
 nbd_set_size+0x4c5/0x7d0
 nbd_genl_reconfigure+0x7e1/0x1040
 genl_family_rcv_msg_doit+0x233/0x340
 genl_rcv_msg+0x614/0x7a0
 netlink_rcv_skb+0x226/0x4a0
 genl_rcv+0x28/0x40
 netlink_unicast+0x7bd/0x940
 netlink_sendmsg+0x813/0xb40
 sock_sendmsg_nosec+0x13a/0x180
 ____sys_sendmsg+0x54e/0x850
 ___sys_sendmsg+0x2a5/0x360
 __x64_sys_sendmsg+0x1b1/0x290
 do_syscall_64+0x166/0x520
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3bceb9e159
RSP: 002b:00007f3bcfa1f028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f3bcee25fa0 RCX: 00007f3bceb9e159
RDX: 0000000004000080 RSI: 00002000000005c0 RDI: 0000000000000004
RBP: 00007f3bcec3506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3bcee26038 R14: 00007f3bcee25fa0 R15: 00007ffcb62f7728
 </TASK>
INFO: task syz.5.29423:14344 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.29423     state:D stack:27872 pid:14344 tgid:14338 ppid:12981  task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17db/0x58f0
 schedule+0x164/0x2b0
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7c1/0x1550
 genl_rcv_msg+0x10b/0x7a0
 netlink_rcv_skb+0x226/0x4a0
 genl_rcv+0x28/0x40
 netlink_unicast+0x7bd/0x940
 netlink_sendmsg+0x813/0xb40
 sock_sendmsg_nosec+0x13a/0x180
 __sys_sendto+0x408/0x5a0
 __x64_sys_sendto+0xde/0x100
 do_syscall_64+0x166/0x520
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc69d35e98e
RSP: 002b:00007fc69e1b0e88 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007fc69e1b26c0 RCX: 00007fc69d35e98e
RDX: 0000000000000020 RSI: 00007fc69e1b1000 RDI: 0000000000000009
RBP: 0000000000000000 R08: 00007fc69e1b0f04 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000009
R13: 00007fc69e1b0f58 R14: 00007fc69e1b1000 R15: 0000000000000000
 </TASK>
INFO: task syz.5.29423:14349 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.29423     state:D stack:27872 pid:14349 tgid:14338 ppid:12981  task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17db/0x58f0
 schedule+0x164/0x2b0
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7c1/0x1550
 genl_rcv_msg+0x10b/0x7a0
 netlink_rcv_skb+0x226/0x4a0
 genl_rcv+0x28/0x40
 netlink_unicast+0x7bd/0x940
 netlink_sendmsg+0x813/0xb40
 sock_sendmsg_nosec+0x13a/0x180
 __sys_sendto+0x408/0x5a0
 __x64_sys_sendto+0xde/0x100
 do_syscall_64+0x166/0x520
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc69d35e98e
RSP: 002b:00007fc69e18fe88 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007fc69e1916c0 RCX: 00007fc69d35e98e
RDX: 0000000000000020 RSI: 00007fc69e190000 RDI: 000000000000000b
RBP: 0000000000000000 R08: 00007fc69e18ff04 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000000b
R13: 00007fc69e18ff58 R14: 00007fc69e190000 R15: 0000000000000000
 </TASK>
INFO: task syz.5.29423:14352 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.29423     state:D stack:25768 pid:14352 tgid:14338 ppid:12981  task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17db/0x58f0
 schedule+0x164/0x2b0
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7c1/0x1550
 genl_rcv_msg+0x10b/0x7a0
 netlink_rcv_skb+0x226/0x4a0
 genl_rcv+0x28/0x40
 netlink_unicast+0x7bd/0x940
 netlink_sendmsg+0x813/0xb40
 sock_sendmsg_nosec+0x13a/0x180
 __sys_sendto+0x408/0x5a0
 __x64_sys_sendto+0xde/0x100
 do_syscall_64+0x166/0x520
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc69d35e98e
RSP: 002b:00007fc69adf0e88 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007fc69adf26c0 RCX: 00007fc69d35e98e
RDX: 0000000000000024 RSI: 00007fc69adf1000 RDI: 0000000000000005
RBP: 0000000000000000 R08: 00007fc69adf0f04 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000005
R13: 00007fc69adf0f58 R14: 00007fc69adf1000 R15: 0000000000000000
 </TASK>
INFO: task syz.6.29429:14358 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.29429     state:D stack:25624 pid:14358 tgid:14357 ppid:12992  task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17db/0x58f0
 schedule+0x164/0x2b0
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7c1/0x1550
 genl_rcv_msg+0x10b/0x7a0
 netlink_rcv_skb+0x226/0x4a0
 genl_rcv+0x28/0x40
 netlink_unicast+0x7bd/0x940
 netlink_sendmsg+0x813/0xb40
 sock_sendmsg_nosec+0x13a/0x180
 __sys_sendto+0x408/0x5a0
 __x64_sys_sendto+0xde/0x100
 do_syscall_64+0x166/0x520
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ffa0995e98e
RSP: 002b:00007ffa0a79de88 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RA
RAX: ffffffffffffffda RBX: 00007ffa0a79f6c0 RCX: 00007ffa0995e98e
RDX: 0000000000000020 RSI: 00007ffa0a79e000 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007ffa0a79df04 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 00007ffa0a79df58 R14: 00007ffa0a79e000 R15: 0000000000000000
 </TASK>
INFO: task syz.6.29429:14359 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.29429     state:D stack:28752 pid:14359 tgid:14357 ppid:12992  task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17db/0x58f0
 schedule+0x164/0x2b0
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7c1/0x1550
 genl_rcv_msg+0x10b/0x7a0
 netlink_rcv_skb+0x226/0x4a0
 genl_rcv+0x28/0x40
 netlink_unicast+0x7bd/0x940
 netlink_sendmsg+0x813/0xb40
 sock_sendmsg_nosec+0x13a/0x180
 __sys_sendto+0x408/0x5a0
 __x64_sys_sendto+0xde/0x100
 do_syscall_64+0x166/0x520
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ffa0995e98e
RSP: 002b:00007ffa0a77ce88 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007ffa0a77e6c0 RCX: 00007ffa0995e98e
RDX: 0000000000000020 RSI: 00007ffa0a77d000 RDI: 0000000000000009
RBP: 0000000000000000 R08: 00007ffa0a77cf04 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000009
R13: 00007ffa0a77cf58 R14: 00007ffa0a77d000 R15: 0000000000000000
 </TASK>
INFO: task syz.6.29429:14360 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.29429     state:D stack:28552 pid:14360 tgid:14357 ppid:12992  task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17db/0x58f0
 schedule+0x164/0x2b0
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7c1/0x1550
 genl_rcv_msg+0x10b/0x7a0
 netlink_rcv_skb+0x226/0x4a0
 genl_rcv+0x28/0x40
 netlink_unicast+0x7bd/0x940
 netlink_sendmsg+0x813/0xb40
 sock_sendmsg_nosec+0x13a/0x180
 __sys_sendto+0x408/0x5a0
 __x64_sys_sendto+0xde/0x100
 do_syscall_64+0x166/0x520
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ffa0995e98e
RSP: 002b:00007ffa07bf4e88 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007ffa07bf66c0 RCX: 00007ffa0995e98e
RDX: 0000000000000020 RSI: 00007ffa07bf5000 RDI: 000000000000000d
RBP: 0000000000000000 R08: 00007ffa07bf4f04 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000000d
R13: 00007ffa07bf4f58 R14: 00007ffa07bf5000 R15: 0000000000000000
 </TASK>

Showing all locks held in the system:
locks held by khungtaskd/35: 1, last CPU#1:
 #0: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
locks held by getty/5422: 2, on CPU#0:
 #0: ffff88816fa440a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900034762e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360
locks held by udevd/4059: 1, on CPU#1:
 #0: ffff88810a3e1350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd70
locks held by udevd/4060: 1, on CPU#1:
 #0: ffff88810a345350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd70
locks held by syz.4.29418/14326: 6, on CPU#1:
 #0: ffffffff902c36e8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff902c3520 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
 #2: ffff88810a275260 (&nbd->config_lock){+.+.}-{4:4}, at: nbd_genl_reconfigure+0x4a6/0x1040
 #3: ffff88810a2aa288 (&q->limits_lock){+.+.}-{4:4}, at: nbd_set_size+0x284/0x7d0
 #4: ffff88810a2a9c50 (&q->q_usage_counter(io)#53){++++}-{0:0}, at: queue_limits_commit_update_frozen+0x55/0xd0
 #5: ffff88810a2a9c88 (&q->q_usage_counter(queue)#37){+.+.}-{0:0}, at: queue_limits_commit_update_frozen+0x55/0xd0
locks held by syz.5.29423/14344: 2, on CPU#1:
 #0: ffffffff902c36e8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff902c3520 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
locks held by syz.5.29423/14349: 2, on CPU#0:
 #0: ffffffff902c36e8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff902c3520 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
locks held by syz.5.29423/14352: 2, on CPU#1:
 #0: ffffffff902c36e8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff902c3520 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
locks held by syz.6.29429/14358: 2, on CPU#1:
 #0: ffffffff902c36e8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff902c3520 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
locks held by syz.6.29429/14359: 2, on CPU#1:
 #0: ffffffff902c36e8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff902c3520 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
locks held by syz.6.29429/14360: 2, on CPU#0:
 #0: ffffffff902c36e8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff902c3520 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
locks held by syz-executor/14398: 2, on CPU#0:
 #0: ffffffff902c36e8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff902c3520 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
locks held by syz-executor/14400: 2, on CPU#1:
 #0: ffffffff902c36e8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff902c3520 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
locks held by syz-executor/14434: 2, on CPU#1:
 #0: ffffffff902c36e8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff902c3520 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
locks held by syz-executor/14454: 2, on CPU#1:
 #0: ffffffff902c36e8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff902c3520 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
locks held by syz-executor/14472: 2, on CPU#0:
 #0: ffffffff902c36e8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff902c3520 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
locks held by syz-executor/14490: 2, on CPU#1:
 #0: ffffffff902c36e8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff902c3520 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
locks held by syz-executor/14510: 2, on CPU#0:
 #0: ffffffff902c36e8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff902c3520 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
locks held by syz-executor/14528: 2, on CPU#1:
 #0: ffffffff902c36e8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff902c3520 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
locks held by syz-executor/14546: 2, on CPU#1:
 #0: ffffffff902c36e8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff902c3520 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0

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

NMI backtrace for cpu 1
CPU: 1 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+0x17d/0x390
 sys_info+0x135/0x170
 watchdog+0xfd7/0x1030
 kthread+0x38b/0x480
 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: 15 Comm: ksoftirqd/0 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:native_apic_msr_write+0x39/0x50
Code: 74 2a 83 ff 30 74 25 eb 10 81 ff d0 00 00 00 74 1b 81 ff e0 00 00 00 74 13 c1 ef 04 81 c7 00 08 00 00 89 f9 89 f0 31 d2 0f 30 <66> 90 c3 cc cc cc cc cc 89 f6 31 d2 e9 26 6d a6 03 66 0f 1f 44 00
RSP: 0018:ffffc90000147ab0 EFLAGS: 00000046
RAX: 000000000000b593 RBX: ffff888121023c80 RCX: 0000000000000838
RDX: 0000000000000000 RSI: 000000000000b593 RDI: 0000000000000838
RBP: ffffc90000147b70 R08: 0000000000000100 R09: 0000000000000001
R10: 0000000000000003 R11: ffffffff81754510 R12: 000000000000b593
R13: dffffc0000000000 R14: 0000000010000a10 R15: 0000000000000020
FS:  0000000000000000(0000) GS:ffff88818d6d1000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000056428878f828 CR3: 000000011a2f8000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 lapic_next_event+0x11/0x20
 clockevents_program_event+0x385/0x630
 __hrtimer_rearm_deferred+0x36c/0x4b0
 irqentry_exit+0x8d3/0x910
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:_raw_spin_unlock_irqrestore+0x47/0x80
Code: f7 e8 8d 03 bc f5 f7 c3 00 02 00 00 74 05 e8 50 47 e8 f5 9c 58 a9 00 02 00 00 75 29 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 94 12 ad f5 65 48 8b 05 0c 21 ad 07 48 85 c0 74 18 5b 41 5e e9
RSP: 0018:ffffc90000147cc8 EFLAGS: 00000206
RAX: 0000000000000002 RBX: 0000000000000283 RCX: 8000000000000101
RDX: 0000000000000000 RSI: ffffffff8e476b04 RDI: 0000000000000001
RBP: 0000000000000008 R08: ffffffff907a357f R09: 1ffffffff20f46af
R10: dffffc0000000000 R11: fffffbfff20f46b0 R12: 0000000000000009
R13: 0000000000000008 R14: ffff888121028280 R15: 0000000000000100
 handle_softirqs+0x226/0x860
 run_ksoftirqd+0x36/0x60
 smpboot_thread_fn+0x565/0xa70
 kthread+0x38b/0x480
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
