INFO: task syz-executor.4:8284 blocked for more than 143 seconds.
      Not tainted 5.15.152-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.4  state:D stack:    0 pid: 8284 ppid:  4006 flags:0x0000000d
Call trace:
 __switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0xf10/0x1e48 kernel/sched/core.c:6376
 schedule+0x11c/0x1c8 kernel/sched/core.c:6459
 schedule_timeout+0xb8/0x344 kernel/time/timer.c:1860
 do_wait_for_common+0x214/0x388 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+0x4c/0x64 kernel/sched/completion.c:138
 flush_workqueue+0x580/0x11c4 kernel/workqueue.c:2882
 nbd_start_device_ioctl drivers/block/nbd.c:1365 [inline]
 __nbd_ioctl drivers/block/nbd.c:1427 [inline]
 nbd_ioctl+0x8c8/0xc2c drivers/block/nbd.c:1467
 blkdev_ioctl+0x3d8/0xbd0 block/ioctl.c:604
 block_ioctl+0xa8/0x114 block/fops.c:493
 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+0x14c/0x1c8 fs/ioctl.c:860
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffff800014ae14a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:268
3 locks held by kworker/u4:5/373:
3 locks held by kworker/0:2/1524:
 #0: ffff0000c0020938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x66c/0x11b8 kernel/workqueue.c:2283
 #1: ffff800020af7c00 (fqdir_free_work){+.+.}-{0:0}, at: process_one_work+0x6ac/0x11b8 kernel/workqueue.c:2285
 #2: ffff800014ae59b0 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x54/0x4b0 kernel/rcu/tree.c:4039
1 lock held by udevd/3583:
2 locks held by getty/3718:
 #0: ffff0000d34d8098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x40/0x50 drivers/tty/tty_ldsem.c:340
 #1: ffff80001a14e2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x414/0x1204 drivers/tty/n_tty.c:2158
2 locks held by kworker/u5:2/4001:
 #0: ffff0000cbe72138 ((wq_completion)nbd4-recv){+.+.}-{0:0}, at: process_one_work+0x66c/0x11b8 kernel/workqueue.c:2283
 #1: ffff80001cc57c00 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x6ac/0x11b8 kernel/workqueue.c:2285
3 locks held by kworker/0:8/4070:
 #0: ffff0000c0020938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x66c/0x11b8 kernel/workqueue.c:2283
 #1: ffff80001d047c00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x6ac/0x11b8 kernel/workqueue.c:2285
 #2: ffff0000d83e2240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x274/0x33c4 drivers/net/netdevsim/fib.c:1478
2 locks held by syz-executor.1/16138:
2 locks held by syz-executor.2/16144:
1 lock held by syz-executor.3/16151:
 #0: ffff0000dc158210 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:789 [inline]
 #0: ffff0000dc158210 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release net/socket.c:648 [inline]
 #0: ffff0000dc158210 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: sock_close+0x80/0x1fc net/socket.c:1336
1 lock held by syz-executor.0/16159:

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