INFO: task syz-executor181:3581 blocked for more than 143 seconds.
      Not tainted 6.1.45-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor181 state:D stack:27160 pid:3581  ppid:3546   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5241 [inline]
 __schedule+0x132c/0x4330 kernel/sched/core.c:6554
 schedule+0xbf/0x180 kernel/sched/core.c:6630
 blk_mq_freeze_queue_wait+0xf8/0x180 block/blk-mq.c:180
 nbd_add_socket+0x1a1/0x8e0 drivers/block/nbd.c:1127
 __nbd_ioctl drivers/block/nbd.c:1470 [inline]
 nbd_ioctl+0x261/0xe70 drivers/block/nbd.c:1527
 blkdev_ioctl+0x3a9/0x760 block/ioctl.c:615
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f617c041479
RSP: 002b:00007f617bfff228 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f617c0c8328 RCX: 00007f617c041479
RDX: 0000000000000004 RSI: 000000000000ab00 RDI: 0000000000000003
RBP: 00007f617c0c8320 R08: 00007f617bfff6c0 R09: 00007f617bfff6c0
R10: 00007f617bfff6c0 R11: 0000000000000246 R12: 00007f617c0c832c
R13: 00007f617c0951a4 R14: 64626e2f7665642f R15: 00007ffd6619eb58
 </TASK>

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
 #0: ffffffff8d12a0b0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xd20 kernel/rcu/tasks.h:516
1 lock held by rcu_tasks_trace/13:
 #0: ffffffff8d12a8b0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xd20 kernel/rcu/tasks.h:516
1 lock held by khungtaskd/28:
 #0: ffffffff8d129ee0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by getty/3272:
 #0: ffff88814b8ae098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
 #1: ffffc900031262f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a7/0x1db0 drivers/tty/n_tty.c:2188
1 lock held by syz-executor181/3581:
 #0: ffff88801fdc4198 (&nbd->config_lock){+.+.}-{3:3}, at: nbd_ioctl+0x149/0xe70 drivers/block/nbd.c:1520
1 lock held by syz-executor181/3583:
 #0: ffff88801fdc4198 (&nbd->config_lock){+.+.}-{3:3}, at: nbd_ioctl+0x149/0xe70 drivers/block/nbd.c:1520
1 lock held by udevd/3582:
 #0: ffff888143bd54c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x148/0xa10 block/bdev.c:813

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

NMI backtrace for cpu 1
CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.1.45-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 nmi_cpu_backtrace+0x4e1/0x560 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x1b0/0x3f0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
 watchdog+0xf18/0xf60 kernel/hung_task.c:377
 kthread+0x26e/0x300 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 1188 Comm: kworker/u4:5 Not tainted 6.1.45-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:cpus_read_unlock+0x6c/0x130 kernel/cpu.c:322
Code: 86 37 00 85 db 74 5b e8 62 83 37 00 eb 05 e8 5b 83 37 00 8b 1d b5 f9 a9 0b 31 ff 89 de e8 ac 86 37 00 85 db 0f 85 8c 00 00 00 <e8> 3f 83 37 00 48 8b 05 00 fa a9 0b 65 ff 08 bf 01 00 00 00 e8 ab
RSP: 0018:ffffc90005f57b30 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff8880225a3b80
RDX: ffff8880225a3b80 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90005f57c50 R08: ffffffff81527ab4 R09: fffffbfff1ce6f6e
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: 1ffff92000beaf68 R14: 0000000000000001 R15: ffff888012479800
FS:  0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffcf4aadc18 CR3: 000000000ce8e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 toggle_allocation_gate+0xbf/0x480 mm/kfence/core.c:804
 process_one_work+0x8aa/0x11f0 kernel/workqueue.c:2292
 worker_thread+0xa5f/0x1210 kernel/workqueue.c:2439
 kthread+0x26e/0x300 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
 </TASK>
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.087 msecs