INFO: task syz-executor.0:14195 blocked for more than 430 seconds.
      Not tainted 5.15.0-syzkaller-12999-gc8c109546a19 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.0  state:D stack:    0 pid:14195 ppid:  4743 flags:0x00000001
Call trace:
 __switch_to+0x264/0x3a4 arch/arm64/kernel/process.c:526
 context_switch kernel/sched/core.c:4969 [inline]
 __schedule+0x868/0x1c14 kernel/sched/core.c:6250
 schedule+0xfc/0x2fc kernel/sched/core.c:6323
 blk_mq_freeze_queue_wait+0xf4/0x130 block/blk-mq.c:178
 blk_freeze_queue block/blk-mq.c:205 [inline]
 blk_mq_freeze_queue+0x20/0x30 block/blk-mq.c:214
 nbd_add_socket+0x134/0x690 drivers/block/nbd.c:1109
 __nbd_ioctl drivers/block/nbd.c:1454 [inline]
 nbd_ioctl+0x430/0x8f4 drivers/block/nbd.c:1511
 blkdev_ioctl+0x238/0x950 block/ioctl.c:609
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl fs/ioctl.c:860 [inline]
 __arm64_sys_ioctl+0x120/0x18c fs/ioctl.c:860
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x6c/0x260 arch/arm64/kernel/syscall.c:52
 el0_svc_common.constprop.0+0xc4/0x254 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0xa0/0xcc arch/arm64/kernel/syscall.c:181
 el0_svc+0x64/0x280 arch/arm64/kernel/entry-common.c:603
 el0t_64_sync_handler+0x1a4/0x1b0 arch/arm64/kernel/entry-common.c:621
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:572

Showing all locks held in the system:
1 lock held by khungtaskd/26:
 #0: ffff800015f7f760 (rcu_read_lock){....}-{1:2}, at: __preempt_count_add arch/arm64/include/asm/preempt.h:48 [inline]
 #0: ffff800015f7f760 (rcu_read_lock){....}-{1:2}, at: __rcu_read_lock include/linux/rcupdate.h:68 [inline]
 #0: ffff800015f7f760 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:686 [inline]
 #0: ffff800015f7f760 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0xd4/0x368 kernel/locking/lockdep.c:6464
1 lock held by syslogd/1994:
2 locks held by getty/2157:
 #0: ffff00000e415098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3c/0x50 drivers/tty/tty_ldsem.c:340
 #1: ffff80001899b2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x810/0xbe0 drivers/tty/n_tty.c:2113
1 lock held by syz-executor.0/14195:
 #0: ffff000010a06198 (&nbd->config_lock){+.+.}-{3:3}, at: nbd_ioctl+0x108/0x8f4 drivers/block/nbd.c:1504

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