INFO: task syz.0.3871:19536 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.3871      state:D stack:25000 pid:19536 tgid:19535 ppid:5828   task_flags:0x480140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x14ef/0x4fb0
 schedule+0x164/0x360
 blk_mq_freeze_queue_wait+0x101/0x180
 queue_limits_commit_update_frozen+0x55/0xd0
 nbd_set_size+0x516/0x6d0
 nbd_genl_size_set+0x32c/0x400
 nbd_genl_reconfigure+0x428/0x1a70
 genl_family_rcv_msg_doit+0x22a/0x330
 genl_rcv_msg+0x61c/0x7a0
 netlink_rcv_skb+0x232/0x4b0
 genl_rcv+0x28/0x40
 netlink_unicast+0x80f/0x9b0
 netlink_sendmsg+0x813/0xb40
 __sock_sendmsg+0x21c/0x270
 ____sys_sendmsg+0x4d7/0x810
 ___sys_sendmsg+0x2a5/0x360
 __x64_sys_sendmsg+0x1bd/0x2a0
 do_syscall_64+0xe2/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f52b079acb9
RSP: 002b:00007f52b160d028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f52b0a15fa0 RCX: 00007f52b079acb9
RDX: 0000000000048000 RSI: 0000200000000380 RDI: 000000000000000e
RBP: 00007f52b0808bf7 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f52b0a16038 R14: 00007f52b0a15fa0 R15: 00007fff989f6fe8
 </TASK>
INFO: task syz.2.3869:19539 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.3869      state:D stack:27776 pid:19539 tgid:19538 ppid:5829   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x14ef/0x4fb0
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7fe/0x1300
 genl_rcv_msg+0x10b/0x7a0
 netlink_rcv_skb+0x232/0x4b0
 genl_rcv+0x28/0x40
 netlink_unicast+0x80f/0x9b0
 netlink_sendmsg+0x813/0xb40
 __sock_sendmsg+0x21c/0x270
 __sys_sendto+0x3c0/0x550
 __x64_sys_sendto+0xde/0x100
 do_syscall_64+0xe2/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe88875b58e
RSP: 002b:00007fe88969de88 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007fe88969f6c0 RCX: 00007fe88875b58e
RDX: 0000000000000020 RSI: 00007fe88969e000 RDI: 0000000000000005
RBP: 0000000000000000 R08: 00007fe88969df04 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000005
R13: 00007fe88969df58 R14: 00007fe88969e000 R15: 0000000000000000
 </TASK>
INFO: task syz.2.3869:19542 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.3869      state:D stack:25248 pid:19542 tgid:19538 ppid:5829   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x14ef/0x4fb0
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7fe/0x1300
 genl_rcv_msg+0x10b/0x7a0
 netlink_rcv_skb+0x232/0x4b0
 genl_rcv+0x28/0x40
 netlink_unicast+0x80f/0x9b0
 netlink_sendmsg+0x813/0xb40
 __sock_sendmsg+0x21c/0x270
 __sys_sendto+0x3c0/0x550
 __x64_sys_sendto+0xde/0x100
 do_syscall_64+0xe2/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe88875b58e
RSP: 002b:00007fe88967ce88 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007fe88967e6c0 RCX: 00007fe88875b58e
RDX: 0000000000000020 RSI: 00007fe88967d000 RDI: 000000000000000c
RBP: 0000000000000000 R08: 00007fe88967cf04 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000000c
R13: 00007fe88967cf58 R14: 00007fe88967d000 R15: 0000000000000000
 </TASK>
INFO: task syz.1.3873:19551 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.3873      state:D stack:28704 pid:19551 tgid:19549 ppid:5824   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x14ef/0x4fb0
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7fe/0x1300
 genl_rcv_msg+0x10b/0x7a0
 netlink_rcv_skb+0x232/0x4b0
 genl_rcv+0x28/0x40
 netlink_unicast+0x80f/0x9b0
 netlink_sendmsg+0x813/0xb40
 __sock_sendmsg+0x21c/0x270
 __sys_sendto+0x3c0/0x550
 __x64_sys_sendto+0xde/0x100
 do_syscall_64+0xe2/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f27b7f5b58e
RSP: 002b:00007f27b8f18e88 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f27b8f1a6c0 RCX: 00007f27b7f5b58e
RDX: 0000000000000020 RSI: 00007f27b8f19000 RDI: 0000000000000007
RBP: 0000000000000000 R08: 00007f27b8f18f04 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000007
R13: 00007f27b8f18f58 R14: 00007f27b8f19000 R15: 0000000000000000
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/35:
 #0: ffffffff8e35a320 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5654:
 #0: ffff8881066da0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000356e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0
1 lock held by udevd/8108:
 #0: ffff88816b1a1358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30
1 lock held by udevd/12058:
 #0: ffff88811531e358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30
6 locks held by syz.0.3871/19536:
 #0: ffffffff8f816b30 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f816948 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
 #2: ffff88810ffa0278 (&nbd->config_lock){+.+.}-{4:4}, at: nbd_genl_reconfigure+0x38e/0x1a70
 #3: ffff88810a611048 (&q->limits_lock){+.+.}-{4:4}, at: nbd_set_size+0x2ba/0x6d0
 #4: ffff88810a6109e8 (&q->q_usage_counter(io)#70){++++}-{0:0}, at: queue_limits_commit_update_frozen+0x55/0xd0
 #5: ffff88810a610a20 (&q->q_usage_counter(queue)#53){+.+.}-{0:0}, at: queue_limits_commit_update_frozen+0x55/0xd0
2 locks held by syz.2.3869/19539:
 #0: ffffffff8f816b30 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f816948 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
2 locks held by syz.2.3869/19542:
 #0: ffffffff8f816b30 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f816948 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
2 locks held by syz.1.3873/19551:
 #0: ffffffff8f816b30 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f816948 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
2 locks held by syz-executor/19557:
 #0: ffffffff8f816b30 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f816948 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
2 locks held by syz-executor/19559:
 #0: ffffffff8f816b30 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f816948 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
2 locks held by syz-executor/19561:
 #0: ffffffff8f816b30 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f816948 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
2 locks held by syz-executor/19590:
 #0: ffffffff8f816b30 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f816948 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
2 locks held by syz-executor/19592:
 #0: ffffffff8f816b30 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f816948 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
2 locks held by syz-executor/19594:
 #0: ffffffff8f816b30 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f816948 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
2 locks held by syz-executor/19623:
 #0: ffffffff8f816b30 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f816948 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
2 locks held by syz-executor/19625:
 #0: ffffffff8f816b30 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f816948 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
2 locks held by syz-executor/19627:
 #0: ffffffff8f816b30 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f816948 (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+0x17a/0x300
 sys_info+0x135/0x170
 watchdog+0xf90/0xfe0
 kthread+0x726/0x8b0
 ret_from_fork+0x51b/0xa40
 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: 0 Comm: swapper/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:pv_native_safe_halt+0xf/0x20
Code: 78 5f 02 e9 d3 e5 02 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d d3 c7 10 00 fb f4 <c3> cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
RSP: 0018:ffffffff8e007dc0 EFLAGS: 00000206
RAX: 0000000000363217 RBX: ffffffff8198335d RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8dad4654 RDI: ffffffff8be73880
RBP: ffffffff8e007eb0 R08: ffff8881210336db R09: 1ffff110242066db
R10: dffffc0000000000 R11: ffffed10242066dc R12: ffffffff8fced870
R13: 1ffffffff1c12a78 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff88818e329000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000558114da2038 CR3: 000000000e146000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 default_idle+0x9/0x20
 default_idle_call+0x72/0xb0
 do_idle+0x1bd/0x500
 cpu_startup_entry+0x43/0x60
 rest_init+0x2de/0x300
 start_kernel+0x380/0x3d0
 x86_64_start_reservations+0x24/0x30
 x86_64_start_kernel+0x143/0x1c0
 common_startup_64+0x13e/0x147
 </TASK>
