INFO: task syz-executor.0:6713 blocked for more than 143 seconds. Not tainted 6.4.0-rc5-syzkaller-00103-g177239177378 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:0 pid:6713 ppid:6327 flags:0x00000009 Call trace: __switch_to+0x320/0x754 arch/arm64/kernel/process.c:556 context_switch kernel/sched/core.c:5343 [inline] __schedule+0x1368/0x23b8 kernel/sched/core.c:6669 schedule+0xc4/0x170 kernel/sched/core.c:6745 schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:6804 __mutex_lock_common+0xbd8/0x21a0 kernel/locking/mutex.c:679 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:799 nbd_start_device_ioctl drivers/block/nbd.c:1427 [inline] __nbd_ioctl drivers/block/nbd.c:1488 [inline] nbd_ioctl+0x8e8/0xc40 drivers/block/nbd.c:1528 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+0x138/0x244 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x64/0x198 arch/arm64/kernel/syscall.c:191 el0_svc+0x4c/0x160 arch/arm64/kernel/entry-common.c:647 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:665 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591 INFO: task syz-executor.0:6714 blocked for more than 143 seconds. Not tainted 6.4.0-rc5-syzkaller-00103-g177239177378 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:0 pid:6714 ppid:6327 flags:0x00000001 Call trace: __switch_to+0x320/0x754 arch/arm64/kernel/process.c:556 context_switch kernel/sched/core.c:5343 [inline] __schedule+0x1368/0x23b8 kernel/sched/core.c:6669 schedule+0xc4/0x170 kernel/sched/core.c:6745 blk_mq_freeze_queue_wait+0xf4/0x174 block/blk-mq.c:146 blk_freeze_queue+0xc8/0x104 block/blk-mq.c:173 blk_mq_freeze_queue+0x20/0x30 block/blk-mq.c:182 nbd_add_socket+0x174/0x770 drivers/block/nbd.c:1128 __nbd_ioctl drivers/block/nbd.c:1471 [inline] nbd_ioctl+0x20c/0xc40 drivers/block/nbd.c:1528 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+0x138/0x244 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x64/0x198 arch/arm64/kernel/syscall.c:191 el0_svc+0x4c/0x160 arch/arm64/kernel/entry-common.c:647 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:665 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/13: #0: ffff80008e0916d0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x44/0xcf4 kernel/rcu/tasks.h:518 1 lock held by rcu_tasks_trace/14: #0: ffff80008e091a90 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x44/0xcf4 kernel/rcu/tasks.h:518 1 lock held by khungtaskd/29: #0: ffff80008e091500 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:326 2 locks held by getty/5734: #0: ffff0000da240098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340 #1: ffff800092e362f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x414/0x1210 drivers/tty/n_tty.c:2176 1 lock held by udevd/6325: #0: ffff0000cca6e4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x12c/0x8f8 block/bdev.c:747 1 lock held by syz-executor.0/6713: #0: ffff0000cca7b198 (&nbd->config_lock){+.+.}-{3:3}, at: nbd_start_device_ioctl drivers/block/nbd.c:1427 [inline] #0: ffff0000cca7b198 (&nbd->config_lock){+.+.}-{3:3}, at: __nbd_ioctl drivers/block/nbd.c:1488 [inline] #0: ffff0000cca7b198 (&nbd->config_lock){+.+.}-{3:3}, at: nbd_ioctl+0x8e8/0xc40 drivers/block/nbd.c:1528 1 lock held by syz-executor.0/6714: #0: ffff0000cca7b198 (&nbd->config_lock){+.+.}-{3:3}, at: nbd_ioctl+0x128/0xc40 drivers/block/nbd.c:1521 1 lock held by syz-executor.0/6730: #0: ffff0000cca6e4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x12c/0x8f8 block/bdev.c:747 1 lock held by syz-executor.0/6731: #0: ffff0000cca6e4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x12c/0x8f8 block/bdev.c:747 1 lock held by syz-executor.0/6747: #0: ffff0000cca6e4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x12c/0x8f8 block/bdev.c:747 1 lock held by syz-executor.0/6748: #0: ffff0000cca6e4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x12c/0x8f8 block/bdev.c:747 =============================================