INFO: task syz.0.2747:16668 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.2747      state:D stack:26408 pid:16668 tgid:16666 ppid:5626   task_flags:0x480140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5583 [inline]
 __schedule+0x17dd/0x5820 kernel/sched/core.c:7382
 __schedule_loop kernel/sched/core.c:7459 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7474
 blk_mq_freeze_queue_wait+0xfc/0x180 block/blk-mq.c:191
 blk_mq_freeze_queue include/linux/blk-mq.h:956 [inline]
 queue_limits_commit_update_frozen+0x55/0xd0 block/blk-settings.c:596
 nbd_set_size+0x4c5/0x7d0 drivers/block/nbd.c:383
 nbd_genl_size_set drivers/block/nbd.c:2111 [inline]
 nbd_genl_reconfigure+0x7e1/0x1040 drivers/block/nbd.c:2444
 genl_family_rcv_msg_doit+0x233/0x340 net/netlink/genetlink.c:1114
 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
 genl_rcv_msg+0x614/0x7a0 net/netlink/genetlink.c:1209
 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2580
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline]
 netlink_unicast+0x8ef/0xa80 net/netlink/af_netlink.c:1361
 netlink_
 netlink_sendmsg+0x7f0/0xb20 net/netlink/af_netlink.c:1920
 sock_sendmsg_nosec+0x14e/0x190 net/socket.c:800
 __sock_sendmsg net/socket.c:818 [inline]
 ____sys_sendmsg+0x54e/0x850 net/socket.c:2715
 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2769
 __sys_sendmsg net/socket.c:2801 [inline]
 __do_sys_sendmsg net/socket.c:2806 [inline]
 __se_sys_sendmsg net/socket.c:2804 [inline]
 __x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2804
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe014f9f559
RSP: 002b:00007fe015e68028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fe015225fa0 RCX: 00007fe014f9f559
RDX: 0000000000004004 RSI: 0000200000004ec0 RDI: 0000000000000004
RBP: 00007fe015036b20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe015226038 R14: 00007fe015225fa0 R15: 00007ffdb727c4b8
 </TASK>
INFO: task syz.0.2747:16677 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.2747      state:D stack:28808 pid:16677 tgid:16666 ppid:5626   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5583 [inline]
 __schedule+0x17dd/0x5820 kernel/sched/core.c:7382
 __schedule_loop kernel/sched/core.c:7459 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7474
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7531
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0x7c4/0x15a0 kernel/locking/mutex.c:821
 genl_lock net/netlink/genetlink.c:35 [inline]
 genl_op_lock net/netlink/genetlink.c:60 [inline]
 genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208
 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2580
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline]
 netlink_unicast+0x8ef/0xa80 net/netlink/af_netlink.c:1361
 netlink_sendmsg+0x7f0/0xb20 net/netlink/af_netlink.c:1920
 sock_sendmsg_nosec+0x14e/0x190 net/socket.c:800
 __sock_sendmsg net/socket.c:818 [inline]
 __sys_sendto+0x408/0x5a0 net/socket.c:2283
 __do_sys_sendto net/socket.c:2290 [inline]
 __se_sys_sendto net/socket.c:2286 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2286
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe014f5fd8e
RSP: 002b:00007fe015e45e88 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007fe015e476c0 RCX: 00007fe014f5fd8e
RDX: 0000000000000028 RSI: 00007fe015e46000 RDI: 0000000000000004
RBP: 0000000000000000 R08: 00007fe015e45f04 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000004
R13: 00007fe015e45f58 R14: 00007fe015e46000 R15: 0000000000000000
 </TASK>
INFO: task syz.0.2747:16680 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.2747      state:D stack:28808 pid:16680 tgid:16666 ppid:5626   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5583 [inline]
 __schedule+0x17dd/0x5820 kernel/sched/core.c:7382
 __schedule_loop kernel/sched/core.c:7459 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7474
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7531
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0x7c4/0x15a0 kernel/locking/mutex.c:821
 genl_lock net/netlink/genetlink.c:35 [inline]
 genl_op_lock net/netlink/genetlink.c:60 [inline]
 genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208
 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2580
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline]
 netlink_unicast+0x8ef/0xa80 net/netlink/af_netlink.c:1361
 netlink_sendmsg+0x7f0/0xb20 net/netlink/af_netlink.c:1920
 sock_sendmsg_nosec+0x14e/0x190 net/socket.c:800
 __sock_sendmsg net/socket.c:818 [inline]
 __sys_sendto+0x408/0x5a0 net/socket.c:2283
 __do_sys_sendto net/socket.c:2290 [inline]
 __se_sys_sendto net/socket.c:2286 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2286
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe014f5fd8e
RSP: 002b:00007fe015e24e88 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007fe015e266c0 RCX: 00007fe014f5fd8e
RDX: 0000000000000028 RSI: 00007fe015e25000 RDI: 0000000000000004
RBP: 0000000000000000 R08: 00007fe015e24f04 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000004
R13: 00007fe015e24f58 R14: 00007fe015e25000 R15: 0000000000000000
 </TASK>
INFO: task syz.0.2747:16682 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.2747      state:D stack:27840 pid:16682 tgid:16666 ppid:5626   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5583 [inline]
 __schedule+0x17dd/0x5820 kernel/sched/core.c:7382
 __schedule_loop kernel/sched/core.c:7459 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7474
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7531
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0x7c4/0x15a0 kernel/locking/mutex.c:821
 genl_lock net/netlink/genetlink.c:35 [inline]
 genl_op_lock net/netlink/genetlink.c:60 [inline]
 genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208
 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2580
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline]
 netlink_unicast+0x8ef/0xa80 net/netlink/af_netlink.c:1361
 netlink_sendmsg+0x7f0/0xb20 net/netlink/af_netlink.c:1920
 sock_sendmsg_nosec+0x14e/0x190 net/socket.c:800
 __sock_sendmsg net/socket.c:818 [inline]
 __sys_sendto+0x408/0x5a0 net/socket.c:2283
 __do_sys_sendto net/socket.c:2290 [inline]
 __se_sys_sendto net/socket.c:2286 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2286
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe014f5fd8e
RSP: 002b:00007fe015de2e88 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007fe015de46c0 RCX: 00007fe014f5fd8e
RDX: 0000000000000024 RSI: 00007fe015de3000 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007fe015de2f04 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 00007fe015de2f58 R14: 00007fe015de3000 R15: 0000000000000000
 </TASK>
INFO: task syz.2.2748:16676 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.2748      state:D stack:28808 pid:16676 tgid:16669 ppid:5630   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5583 [inline]
 __schedule+0x17dd/0x5820 kernel/sched/core.c:7382
 __schedule_loop kernel/sched/core.c:7459 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7474
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7531
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0x7c4/0x15a0 kernel/locking/mutex.c:821
 genl_lock net/netlink/genetlink.c:35 [inline]
 genl_op_lock net/netlink/genetlink.c:60 [inline]
 genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208
 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2580
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline]
 netlink_unicast+0x8ef/0xa80 net/netlink/af_netlink.c:1361
 netlink_sendmsg+0x7f0/0xb20 net/netlink/af_netlink.c:1920
 sock_sendmsg_nosec+0x14e/0x190 net/socket.c:800
 __sock_sendmsg net/socket.c:818 [inline]
 __sys_sendto+0x408/0x5a0 net/socket.c:2283
 __do_sys_sendto net/socket.c:2290 [inline]
 __se_sys_sendto net/socket.c:2286 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2286
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5f4f55fd8e
RSP: 002b:00007f5f503c6e88 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f5f503c86c0 RCX: 00007f5f4f55fd8e
RDX: 0000000000000024 RSI: 00007f5f503c7000 RDI: 0000000000000004
RBP: 0000000000000000 R08: 00007f5f503c6f04 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000004
R13: 00007f5f503c6f58 R14: 00007f5f503c7000 R15: 0000000000000000
 </TASK>
INFO: task syz-executor:16673 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:22424 pid:16673 tgid:16673 ppid:1      task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5583 [inline]
 __schedule+0x17dd/0x5820 kernel/sched/core.c:7382
 __schedule_loop kernel/sched/core.c:7459 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7474
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7531
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0x7c4/0x15a0 kernel/locking/mutex.c:821
 genl_lock net/netlink/genetlink.c:35 [inline]
 genl_op_lock net/netlink/genetlink.c:60 [inline]
 genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208
 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2580
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline]
 netlink_unicast+0x8ef/0xa80 net/netlink/af_netlink.c:1361
 netlink_sendmsg+0x7f0/0xb20 net/netlink/af_netlink.c:1920
 sock_sendmsg_nosec+0x14e/0x190 net/socket.c:800
 __sock_sendmsg net/socket.c:818 [inline]
 __sys_sendto+0x408/0x5a0 net/socket.c:2283
 __do_sys_sendto net/socket.c:2290 [inline]
 __se_sys_sendto net/socket.c:2286 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2286
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fefa955fd8e
RSP: 002b:00007ffe9dcac738 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 000055557cef0500 RCX: 00007fefa955fd8e
RDX: 0000000000000020 RSI: 00007fefaa354670 RDI: 0000000000000005
RBP: 0000000000000001 R08: 00007ffe9dcac7b4 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000005
R13: 00007ffe9dcac808 R14: 00007fefaa354670 R15: 0000000000000000
 </TASK>
INFO: task syz.4.2751:16704 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.2751      state:D stack:27840 pid:16704 tgid:16701 ppid:5627   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5583 [inline]
 __schedule+0x17dd/0x5820 kernel/sched/core.c:7382
 __schedule_loop kernel/sched/core.c:7459 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7474
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7531
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0x7c4/0x15a0 kernel/locking/mutex.c:821
 genl_lock net/netlink/genetlink.c:35 [inline]
 genl_op_lock net/netlink/genetlink.c:60 [inline]
 genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208
 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2580
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline]
 netlink_unicast+0x8ef/0xa80 net/netlink/af_netlink.c:1361
 netlink_sendmsg+0x7f0/0xb20 net/netlink/af_netlink.c:1920
 sock_sendmsg_nosec+0x14e/0x190 net/socket.c:800
 __sock_sendmsg net/socket.c:818 [inline]
 __sys_sendto+0x408/0x5a0 net/socket.c:2283
 __do_sys_sendto net/socket.c:2290 [inline]
 __se_sys_sendto net/socket.c:2286 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2286
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fddb3b5fd8e
RSP: 002b:00007fddb4a89e88 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007fddb4a8b6c0 RCX: 00007fddb3b5fd8e
RDX: 0000000000000020 RSI: 00007fddb4a8a000 RDI: 0000000000000004
RBP: 0000000000000000 R08: 00007fddb4a89f04 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000004
R13: 00007fddb4a89f58 R14: 00007fddb4a8a000 R15: 0000000000000000
 </TASK>

Showing all locks held in the system:
locks held by pr/ttyS0/31: 1, last CPU#0:
 #0: ffffffff8fc33858 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:314 [inline]
 #0: ffffffff8fc33858 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:493 [inline]
 #0: ffffffff8fc33858 (console_srcu){....}-{0:0}, at: console_srcu_read_lock+0x30/0x60 kernel/printk/printk.c:291
locks held by khungtaskd/32: 1, last CPU#0:
 #0: ffffffff8fd59ca0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffffffff8fd59ca0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8fd59ca0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871
locks held by klogd/4987: 1, last CPU#0:
 #0: ffffffff8fd59ca0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffffffff8fd59ca0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8fd59ca0 (rcu_read_lock){....}-{1:3}, at: sock_def_readable+0xae/0x550 net/core/sock.c:3736
locks held by getty/5386: 2, on CPU#1:
 #0: ffff8880372d80a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900032432e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211
locks held by syz-executor/5616: 3, last CPU#1:
 #0: ffff88807f341bc0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:544 [inline]
 #0: ffff88807f341bc0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x2d8/0x9f0 mm/mmap.c:1323
 #1: ffffffff8fd59ca0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffffff8fd59ca0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffffff8fd59ca0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
 #1: ffffffff8fd59ca0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0x8f/0x2550 arch/x86/kernel/unwind_orc.c:495
 #2: ffff88801eeae0f0 (&lruvec->lru_lock){....}-{3:3}, at: folio_lruvec_lock_irqsave+0x273/0x550 mm/memcontrol.c:1509
locks held by udevd/12483: 1, on CPU#0:
 #0: ffff888028458350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd70 block/bdev.c:990
locks held by syz.0.2747/16668: 6, on CPU#0:
 #0: ffffffff912db128 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline]
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline]
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208
 #2: ffff88802752ea60 (&nbd->config_lock){+.+.}-{4:4}, at: nbd_genl_reconfigure+0x4a6/0x1040 drivers/block/nbd.c:2435
 #3: ffff88802856c7c8 (&q->limits_lock){+.+.}-{4:4}, at: queue_limits_start_update include/linux/blkdev.h:1101 [inline]
 #3: ffff88802856c7c8 (&q->limits_lock){+.+.}-{4:4}, at: nbd_set_size+0x284/0x7d0 drivers/block/nbd.c:375
 #4: ffff88802856c190 (&q->q_usage_counter(io)#49){++++}-{0:0}, at: blk_mq_freeze_queue include/linux/blk-mq.h:956 [inline]
 #4: ffff88802856c190 (&q->q_usage_counter(io)#49){++++}-{0:0}, at: queue_limits_commit_update_frozen+0x55/0xd0 block/blk-settings.c:596
 #5: ffff88802856c1c8 (&q->q_usage_counter(queue)#33){+.+.}-{0:0}, at: blk_mq_freeze_queue include/linux/blk-mq.h:956 [inline]
 #5: ffff88802856c1c8 (&q->q_usage_counter(queue)#33){+.+.}-{0:0}, at: queue_limits_commit_update_frozen+0x55/0xd0 block/blk-settings.c:596
locks held by syz.0.2747/16677: 2, on CPU#1:
 #0: ffffffff912db128 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline]
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline]
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208
locks held by syz.0.2747/16680: 2, on CPU#1:
 #0: ffffffff912db128 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline]
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline]
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208
locks held by syz.0.2747/16682: 2, on CPU#1:
 #0: ffffffff912db128 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline]
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline]
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208
locks held by syz.2.2748/16676: 2, on CPU#1:
 #0: ffffffff912db128 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline]
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline]
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208
locks held by syz-executor/16673: 2, on CPU#0:
 #0: ffffffff912db128 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline]
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline]
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208
locks held by syz.4.2751/16704: 2, on CPU#1:
 #0: ffffffff912db128 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline]
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline]
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208
locks held by syz-executor/16799: 2, on CPU#0:
 #0: ffffffff912db128 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline]
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline]
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208
locks held by syz-executor/16818: 2, on CPU#0:
 #0: ffffffff912db128 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline]
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline]
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208
locks held by syz-executor/16820: 2, on CPU#0:
 #0: ffffffff912db128 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline]
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline]
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208
locks held by syz-executor/16821: 2, on CPU#0:
 #0: ffffffff912db128 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline]
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline]
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208
locks held by syz.3.2775/16906: 2, on CPU#0:
 #0: ffffffff912db128 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline]
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline]
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208
locks held by syz-executor/16916: 2, on CPU#0:
 #0: ffffffff912db128 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline]
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline]
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208
locks held by syz-executor/16934: 2, on CPU#0:
 #0: ffffffff912db128 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline]
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline]
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208
locks held by syz-executor/16955: 2, on CPU#0:
 #0: ffffffff912db128 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline]
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline]
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208
locks held by syz-executor/16957: 2, on CPU#0:
 #0: ffffffff912db128 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline]
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline]
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208
locks held by syz-executor/16962: 2, on CPU#0:
 #0: ffffffff912db128 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline]
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline]
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208
locks held by syz-executor/17012: 2, on CPU#0:
 #0: ffffffff912db128 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline]
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline]
 #1: ffffffff912daf60 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 32 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:123
 nmi_trigger_cpumask_backtrace+0x17d/0x390 lib/nmi_backtrace.c:66
 trigger_all_cpu_backtrace include/linux/nmi.h:164 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x135/0x170 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
 watchdog+0xfd2/0x1030 kernel/hung_task.c:561
 kthread+0x38b/0x480 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: pr/ttyS0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
RIP: 0010:delay_tsc+0x5d/0xd0 arch/x86/lib/delay.c:77
Code: 89 d7 49 c1 e7 20 49 09 c7 4d 29 f7 49 39 df 73 55 bf 01 00 00 00 e8 42 3c a2 f5 65 48 8b 05 da 6f a8 08 48 85 c0 74 1c f3 90 <bf> 01 00 00 00 e8 d9 3a a2 f5 e8 c4 83 01 00 39 c5 75 0e 0f 01 f9
RSP: 0018:ffffc90000a778b8 EFLAGS: 00000082
RAX: 8000000000000001 RBX: 0000000000000899 RCX: ffffffff9ba49501
RDX: 0000000000000001 RSI: ffffffff8c6e1760 RDI: 00000000ffffffff
RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: ffffffff8bf2dfe0 R12: 1ffffffff37b43b9
R13: 00000000ffffffff R14: 000000e898947dda R15: 000000000000010c
FS:  0000000000000000(0000) GS:ffff888123a6b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555d71115168 CR3: 000000007f56e000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 udelay include/asm-generic/delay.h:62 [inline]
 wait_for_lsr+0x147/0x2f0 drivers/tty/serial/8250/8250_port.c:2019
 serial8250_fifo_wait_for_lsr_thre drivers/tty/serial/8250/8250_port.c:3270 [inline]
 __serial8250_console_fifo_write+0x346/0x3e0 drivers/tty/serial/8250/8250_port.c:3372
 serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3378 [inline]
 __serial8250_console_write drivers/tty/serial/8250/8250_port.c:3432 [inline]
 serial8250_console_write+0xa7e/0x1200 drivers/tty/serial/8250/8250_port.c:3496
 nbcon_emit_next_record+0xef5/0x1a90 kernel/printk/nbcon.c:-1
 nbcon_emit_one kernel/printk/nbcon.c:1157 [inline]
 nbcon_kthread_func+0x6d9/0x8d0 kernel/printk/nbcon.c:1271
 kthread+0x38b/0x480 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>