syzbot

INFO: task syz-executor575:3955 blocked for more than 143 seconds.
      Not tainted 6.1.0-rc8-syzkaller-33330-ga5541c0811a0 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor575 state:D stack:0     pid:3955  ppid:3128   flags:0x00000009
Call trace:
 __switch_to+0x180/0x298 arch/arm64/kernel/process.c:555
 context_switch kernel/sched/core.c:5209 [inline]
 __schedule+0x408/0x594 kernel/sched/core.c:6521
 schedule+0x64/0xa4 kernel/sched/core.c:6597
 schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:6656
 __mutex_lock_common+0x788/0xca8 kernel/locking/mutex.c:679
 __mutex_lock kernel/locking/mutex.c:747 [inline]
 mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799
 nbd_start_device_ioctl+0x1f0/0x2b8 drivers/block/nbd.c:1420
 __nbd_ioctl+0x16c/0x334 drivers/block/nbd.c:1481
 nbd_ioctl+0xec/0x13c drivers/block/nbd.c:1521
 blkdev_ioctl+0x24c/0x6d8 block/ioctl.c:614
 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+0xd0/0x140 fs/ioctl.c:856
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall arch/arm64/kernel/syscall.c:52 [inline]
 el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x48/0x140 arch/arm64/kernel/syscall.c:197
 el0_svc+0x58/0x150 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:584
INFO: task syz-executor575:3956 blocked for more than 143 seconds.
      Not tainted 6.1.0-rc8-syzkaller-33330-ga5541c0811a0 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor575 state:D stack:0     pid:3956  ppid:3128   flags:0x00000001
Call trace:
 __switch_to+0x180/0x298 arch/arm64/kernel/process.c:555
 context_switch kernel/sched/core.c:5209 [inline]
 __schedule+0x408/0x594 kernel/sched/core.c:6521
 schedule+0x64/0xa4 kernel/sched/core.c:6597
 blk_mq_freeze_queue_wait+0x94/0xf4 block/blk-mq.c:180
 blk_freeze_queue+0x94/0xa8 block/blk-mq.c:207
 blk_mq_freeze_queue+0x20/0x30 block/blk-mq.c:216
 nbd_add_socket+0x78/0x27c drivers/block/nbd.c:1121
 __nbd_ioctl+0x80/0x334 drivers/block/nbd.c:1464
 nbd_ioctl+0xec/0x13c drivers/block/nbd.c:1521
 blkdev_ioctl+0x24c/0x6d8 block/ioctl.c:614
 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+0xd0/0x140 fs/ioctl.c:856
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall arch/arm64/kernel/syscall.c:52 [inline]
 el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x48/0x140 arch/arm64/kernel/syscall.c:197
 el0_svc+0x58/0x150 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:584

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/11:
 #0: ffff80000d4a4768 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x3c/0x450 kernel/rcu/tasks.h:507
1 lock held by rcu_tasks_trace/12:
 #0: ffff80000d4a4db8 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x3c/0x450 kernel/rcu/tasks.h:507
1 lock held by khungtaskd/27:
 #0: ffff80000d4a4640 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x4/0x48 include/linux/rcupdate.h:303
1 lock held by klogd/2593:
 #0: ffff0001fefeee98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:537 [inline]
 #0: ffff0001fefeee98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock kernel/sched/sched.h:1354 [inline]
 #0: ffff0001fefeee98 (&rq->__lock){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1644 [inline]
 #0: ffff0001fefeee98 (&rq->__lock){-.-.}-{2:2}, at: __schedule+0xa4/0x594 kernel/sched/core.c:6438
2 locks held by getty/2756:
 #0: ffff0000c809c898 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x28/0x58 drivers/tty/tty_ldisc.c:244
 #1: ffff80000f6be2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x19c/0x89c drivers/tty/n_tty.c:2177
1 lock held by udevd/3129:
 #0: ffff0000c4031cc8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0xfc/0x2fc block/bdev.c:813
1 lock held by syz-executor575/3955:
 #0: ffff0000c56bfd98 (&nbd->config_lock){+.+.}-{3:3}, at: nbd_start_device_ioctl+0x1f0/0x2b8 drivers/block/nbd.c:1420
1 lock held by syz-executor575/3956:
 #0: ffff0000c56bfd98 (&nbd->config_lock){+.+.}-{3:3}, at: nbd_ioctl+0x70/0x13c drivers/block/nbd.c:1514

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