INFO: task dhcpcd:5353 blocked for m
INFO: task dhcpcd:5353 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:dhcpcd          state:D stack:24616 pid:5353  tgid:5353  ppid:1      task_flags:0x400140 flags:0x00080000
Call Trace:
 <TASK>
 __schedule+0x17dd/0x5830
 schedule+0x164/0x2b0
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7c4/0x15a0
 genl_rcv_msg+0x10b/0x7a0
 netlink_rcv_skb+0x226/0x4a0
 genl_rcv+0x28/0x40
 netlink_unicast+0x8ef/0xa80
 netlink_sendmsg+0x7f0/0xb20
 sock_sendmsg_nosec+0x14e/0x190
 ____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: 0033:0x7f793ee02a4b
RSP: 002b:00007ffd958a1e98 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 000055de2a37494f RCX: 00007f793ee02a4b
RDX: 0000000000000000 RSI: 00007ffd958a1ee0 RDI: 0000000000000010
RBP: 00007ffd958aa438 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000010
R13: 00007ffd958a5f40 R14: 0000000000000000 R15: 000055de3d1a6610
 </TASK>
INFO: task syz.0.17670:14834 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.17670     state:D stack:25328 pid:14834 tgid:14833 ppid:5613   task_flags:0x480140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17dd/0x5830
 schedule+0x164/0x2b0
 blk_mq_freeze_queue_wait+0xfc/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+0x8ef/0xa80
 netlink_sendmsg+0x7f0/0xb20
 sock_sendmsg_nosec+0x14e/0x190
 ____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: 0033:0x7efd4f19f559
RSP: 002b:00007efd50115028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007efd4f425fa0 RCX: 00007efd4f19f559
RDX: 0000000000004004 RSI: 0000200000000180 RDI: 0000000000000004
RBP: 00007efd4f236b20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007efd4f426038 R14: 00007efd4f425fa0 R15: 00007ffdc2d45078
 </TASK>
INFO: task syz.2.17671:14844 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.17671     state:D stack:27840 pid:14844 tgid:14843 ppid:5621   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17dd/0x5830
 schedule+0x164/0x2b0
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7c4/0x15a0
 genl_rcv_msg+0x10b/0x7a0
 netlink_rcv_skb+0x226/0x4a0
 genl_rcv+0x28/0x40
 netlink_unicast+0x8ef/0xa80
 netlink_sendmsg+0x7f0/0xb20
 sock_sendmsg_nosec+0x14e/0x190
 __sys_sendto+0x408/0x5a0
 __x64_sys_sendto+0xde/0x100
 do_syscall_64+0x166/0x520
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3f8ef5fd8e
RSP: 002b:00007f3f8feeee88 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f3f8fef06c0 RCX: 00007f3f8ef5fd8e
RDX: 0000000000000020 RSI: 00007f3f8feef000 RDI: 0000000000000004
RBP: 0000000000000000 R08: 00007f3f8feeef04 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000004
R13: 00007f3f8feeef58 R14: 00007f3f8feef000 R15: 0000000000000000
 </TASK>
INFO: task syz.1.17673:14856 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.17673     state:D stack:27840 pid:14856 tgid:14855 ppid:5619   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17dd/0x5830
 schedule+0x164/0x2b0
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7c4/0x15a0
 genl_rcv_msg+0x10b/0x7a0
 netlink_rcv_skb+0x226/0x4a0
 genl_rcv+0x28/0x40
 netlink_unicast+0x8ef/0xa80
 netlink_sendmsg+0x7f0/0xb20
 sock_sendmsg_nosec+0x14e/0x190
 __sys_sendto+0x408/0x5a0
 __x64_sys_sendto+0xde/0x100
 do_syscall_64+0x166/0x520
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6840b5fd8e
RSP: 002b:00007f6841a97e88 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f6841a996c0 RCX: 00007f6840b5fd8e
RDX: 0000000000000020 RSI: 00007f6841a98000 RDI: 0000000000000004
RBP: 0000000000000000 R08: 00007f6841a97f04 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000004
R13: 00007f6841a97f58 R14: 00007f6841a98000 R15: 0000000000000000
 </TASK>
INFO: task syz.1.17673:14857 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.17673     state:D stack:27168 pid:14857 tgid:14855 ppid:5619   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17dd/0x5830
 schedule+0x164/0x2b0
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7c4/0x15a0
 genl_rcv_msg+0x10b/0x7a0
 netlink_rcv_skb+0x226/0x4a0
 genl_rcv+0x28/0x40
 netlink_unicast+0x8ef/0xa80
 netlink_sendmsg+0x7f0/0xb20
 sock_sendmsg_nosec+0x14e/0x190
 ____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: 0033:0x7f6840b9f559
RSP: 002b:00007f6841a78028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f6840e26090 RCX: 00007f6840b9f559
RDX: 0000000000000000 RSI: 0000200000000000 RDI: 000000000000000c
RBP: 00007f6840c36b20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6840e26128 R14: 00007f6840e26090 R15: 00007ffc72bf3e48
 </TASK>

Showing all locks held in the system:
locks held by khungtaskd/36: 1, last CPU#0:
 #0: ffffffff8ff5a320 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
locks held by dhcpcd/5353: 2, on CPU#1:
 #0: ffffffff914f05a8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff914f03e0 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
locks held by getty/5436: 2, on CPU#1:
 #0: ffff88817506e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900034932e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360
locks held by udevd/2756: 1, on CPU#0:
 #0: ffff8881209dc350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd70
locks held by syz.0.17670/14834: 6, on CPU#0:
 #0: ffffffff914f05a8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff914f03e0 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
 #2: ffff88801ee36a18 (&nbd->config_lock){+.+.}-{4:4}, at: nbd_genl_reconfigure+0x4a6/0x1040
 #3: ffff888110f8d118 (&q->limits_lock){+.+.}-{4:4}, at: nbd_set_size+0x284/0x7d0
 #4: ffff888110f8cae0 (&q->q_usage_counter(io)#72){++++}-{0:0}, at: queue_limits_commit_update_frozen+0x55/0xd0
 #5: ffff888110f8cb18 (&q->q_usage_counter(queue)#55){+.+.}-{0:0}, at: queue_limits_commit_update_frozen+0x55/0xd0
locks held by syz.2.17671/14844: 2, on CPU#0:
 #0: ffffffff914f05a8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff914f03e0 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
locks held by syz.1.17673/14856: 2, on CPU#0:
 #0: ffffffff914f05a8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff914f03e0 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
locks held by syz.1.17673/14857: 2, on CPU#0:
 #0: ffffffff914f05a8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff914f03e0 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
locks held by syz-executor/14865: 2, on CPU#0:
 #0: ffffffff914f05a8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff914f03e0 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
locks held by syz-executor/14867: 2, on CPU#0:
 #0: ffffffff914f05a8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff914f03e0 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
locks held by syz-executor/14870: 2, on CPU#1:
 #0: ffffffff914f05a8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff914f03e0 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
locks held by syz-executor/14923: 2, on CPU#0:
 #0: ffffffff914f05a8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff914f03e0 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
locks held by syz-executor/14927: 2, on CPU#0:
 #0: ffffffff914f05a8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff914f03e0 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
locks held by syz-executor/14934: 2, on CPU#0:
 #0: ffffffff914f05a8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff914f03e0 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
locks held by syz-executor/14975: 2, on CPU#0:
 #0: ffffffff914f05a8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff914f03e0 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
locks held by syz-executor/14994: 2, on CPU#0:
 #0: ffffffff914f05a8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff914f03e0 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
locks held by syz-executor/14999: 2, on CPU#1:
 #0: ffffffff914f05a8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff914f03e0 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 36 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+0x1073/0x10f0
 kthread+0x38b/0x480
 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: 35 Comm: pr/ttyS0 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:io_serial_out+0x7c/0xc0
Code: b1 45 fc 44 89 f9 d3 e5 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 7c 8e bc fc 41 03 2e 89 d8 89 ea ee <5b> 41 5c 41 5e 41 5f 5d c3 cc cc cc cc cc 44 89 f9 80 e1 07 38 c1
RSP: 0018:ffffc90000ab7900 EFLAGS: 00000002
RAX: 0000000000000039 RBX: 0000000000000039 RCX: 0000000000000000
RDX: 00000000000003f8 RSI: 0000000000000000 RDI: 0000000000000020
RBP: 00000000000003f8 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: ffffffff85836470 R12: dffffc0000000000
R13: 0000000000000039 R14: ffffffff9bfee700 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8882a7a20000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007faaf3460875 CR3: 00000001166f2000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 __serial8250_console_fifo_write+0x1e6/0x3e0
 serial8250_console_write+0xa7e/0x1200
 nbcon_emit_next_record+0xef5/0x1a90
 nbcon_kthread_func+0x6d9/0x8d0
 kthread+0x38b/0x480
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
