INFO: task syz.0.4129:21624 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.4129      state:D stack:25976 pid:21624 tgid:21623 ppid:5837   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: 0033:0x7f2f7619acb9
RSP: 002b:00007f2f770e8028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f2f76415fa0 RCX: 00007f2f7619acb9
RDX: 0000000000048000 RSI: 0000200000000380 RDI: 000000000000000c
RBP: 00007f2f76208bf7 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2f76416038 R14: 00007f2f76415fa0 R15: 00007ffc8d4a0d48
 </TASK>
INFO: task syz.1.4131:21634 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.4131      state:D stack:27112 pid:21634 tgid:21633 ppid:5833   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: 0033:0x7f781315b58e
RSP: 002b:00007f7814064e88 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f78140666c0 RCX: 00007f781315b58e
RDX: 0000000000000020 RSI: 00007f7814065000 RDI: 0000000000000005
RBP: 0000000000000000 R08: 00007f7814064f04 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000005
R13: 00007f7814064f58 R14: 00007f7814065000 R15: 0000000000000000
 </TASK>
INFO: task syz.2.4132:21639 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.4132      state:D stack:28560 pid:21639 tgid:21638 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: 0033:0x7f2b51b5b58e
RSP: 002b:00007f2b52b35e88 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f2b52b376c0 RCX: 00007f2b51b5b58e
RDX: 0000000000000020 RSI: 00007f2b52b36000 RDI: 0000000000000005
RBP: 0000000000000000 R08: 00007f2b52b35f04 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000005
R13: 00007f2b52b35f58 R14: 00007f2b52b36000 R15: 0000000000000000
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/36:
 #0: ffffffff8e35a320 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5656:
 #0: ffff8881147660a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000356b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0
1 lock held by udevd/12980:
 #0: ffff88816b188358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30
6 locks held by syz.0.4129/21624:
 #0: ffffffff8f816b30 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f816948 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
 #2: ffff88810a1a2a78 (&nbd->config_lock){+.+.}-{4:4}, at: nbd_genl_reconfigure+0x38e/0x1a70
 #3: ffff88810a085c88 (&q->limits_lock){+.+.}-{4:4}, at: nbd_set_size+0x2ba/0x6d0
 #4: ffff88810a085628 (&q->q_usage_counter(io)#49){++++}-{0:0}, at: queue_limits_commit_update_frozen+0x55/0xd0
 #5: ffff88810a085660 (&q->q_usage_counter(queue)#33){+.+.}-{0:0}, at: queue_limits_commit_update_frozen+0x55/0xd0
2 locks held by syz.1.4131/21634:
 #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.2.4132/21639:
 #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/21644:
 #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/21657:
 #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/21658:
 #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/21676:
 #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/21686:
 #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/21688:
 #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/21711:
 #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/21721:
 #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/21723:
 #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 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+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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 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:trace_csd_function_exit+0x0/0x1b0
Code: 00 90 0f 0b 90 e9 36 ff ff ff e8 2b 9b 0b 00 e8 56 c3 7c ff e9 6e fe ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <55> 41 57 41 56 41 54 53 48 89 f3 49 89 fe e8 fd 9a 0b 00 0f 1f 44
RSP: 0018:ffffc90000a08fd8 EFLAGS: 00000082
RAX: 014f94d0f5025e00 RBX: 0000000000000001 RCX: 0000000000010000
RDX: 0000000000000000 RSI: ffff8881bbc30038 RDI: ffffffff81926f40
RBP: 0000000000000001 R08: ffff88823c63a903 R09: 1ffff110478c7520
R10: dffffc0000000000 R11: ffffed10478c7521 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8882a9929000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffe0f659bfc CR3: 000000016d934000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 __sysvec_call_function_single+0x98/0x390
 sysvec_call_function_single+0x9e/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_call_function_single+0x1a/0x20
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:ffffc90000197e20 EFLAGS: 00000202
RAX: 00000000003765f7 RBX: ffffffff8198335d RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8dad4686 RDI: ffffffff8be73880
RBP: ffffc90000197f10 R08: ffff88823c6336db R09: 1ffff110478c66db
R10: dffffc0000000000 R11: ffffed10478c66dc R12: ffffffff8fced770
R13: 1ffff1102c150000 R14: 0000000000000001 R15: 0000000000000001
 default_idle+0x9/0x20
 default_idle_call+0x72/0xb0
 do_idle+0x1bd/0x500
 cpu_startup_entry+0x43/0x60
 start_secondary+0x101/0x110
 common_startup_64+0x13e/0x147
 </TASK>
