INFO: task syz-executor.4:11005 blocked for more than 143 seconds.
      Not tainted 6.3.0-rc5-syzkaller-g9a03cbd79d3a #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.4  state:D stack:0     pid:11005 ppid:6030   flags:0x00000009
Call trace:
 __switch_to+0x320/0x754 arch/arm64/kernel/process.c:556
 context_switch kernel/sched/core.c:5307 [inline]
 __schedule+0x1048/0x1e38 kernel/sched/core.c:6625
 schedule+0xc4/0x170 kernel/sched/core.c:6701
 schedule_timeout+0xb8/0x348 kernel/time/timer.c:2143
 do_wait_for_common+0x30c/0x468 kernel/sched/completion.c:85
 __wait_for_common kernel/sched/completion.c:106 [inline]
 wait_for_common kernel/sched/completion.c:117 [inline]
 wait_for_completion+0x48/0x60 kernel/sched/completion.c:138
 __flush_workqueue+0x580/0x11c4 kernel/workqueue.c:2962
 nbd_start_device_ioctl drivers/block/nbd.c:1420 [inline]
 __nbd_ioctl drivers/block/nbd.c:1482 [inline]
 nbd_ioctl+0x8dc/0xc40 drivers/block/nbd.c:1522
 blkdev_ioctl+0x408/0xb40 block/ioctl.c:615
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl fs/ioctl.c:856 [inline]
 __arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:856
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x64/0x198 arch/arm64/kernel/syscall.c:193
 el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
 #0: ffff800015e5f250 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x44/0xcf4 kernel/rcu/tasks.h:510
1 lock held by rcu_tasks_trace/13:
 #0: ffff800015e5fa50 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x44/0xcf4 kernel/rcu/tasks.h:510
1 lock held by khungtaskd/28:
 #0: ffff800015e5f080 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:326
3 locks held by kworker/u4:4/1725:
2 locks held by getty/5670:
 #0: ffff0000d8444098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340
 #1: ffff80001aac32f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x414/0x1210 drivers/tty/n_tty.c:2177
2 locks held by kworker/u5:2/6025:
 #0: ffff0000cbc67938 ((wq_completion)nbd4-recv){+.+.}-{0:0}, at: process_one_work+0x664/0x12d4 kernel/workqueue.c:2363
 #1: ffff80001e577c20 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x6a8/0x12d4 kernel/workqueue.c:2365
2 locks held by kworker/u4:7/6284:
1 lock held by udevd/13113:
2 locks held by udevd/13154:
2 locks held by udevd/13156:
1 lock held by syz-executor.0/14633:
1 lock held by syz-executor.5/14625:
2 locks held by syz-executor.2/14631:

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