INFO: task syz-executor.4:2711 blocked for more than 143 seconds. Not tainted 6.4.0-rc2-syzkaller-gf1fcbaa18b28 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.4 state:D stack:0 pid:2711 ppid:6031 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+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x64/0x198 arch/arm64/kernel/syscall.c:193 el0_svc+0x4c/0x15c 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 INFO: task syz-executor.4:2719 blocked for more than 143 seconds. Not tainted 6.4.0-rc2-syzkaller-gf1fcbaa18b28 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.4 state:D stack:0 pid:2719 ppid:6031 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 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 blkdev_get_by_dev+0x12c/0x8f8 block/bdev.c:747 blkdev_open+0x10c/0x290 block/fops.c:493 do_dentry_open+0x724/0xf90 fs/open.c:920 vfs_open+0x7c/0x90 fs/open.c:1051 do_open fs/namei.c:3636 [inline] path_openat+0x1f2c/0x27f8 fs/namei.c:3791 do_filp_open+0x1bc/0x3cc fs/namei.c:3818 do_sys_openat2+0x128/0x3d8 fs/open.c:1356 do_sys_open fs/open.c:1372 [inline] __do_sys_openat fs/open.c:1388 [inline] __se_sys_openat fs/open.c:1383 [inline] __arm64_sys_openat+0x1f0/0x240 fs/open.c:1383 __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+0x4c/0x15c 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 INFO: task syz-executor.4:2723 blocked for more than 143 seconds. Not tainted 6.4.0-rc2-syzkaller-gf1fcbaa18b28 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.4 state:D stack:0 pid:2723 ppid:6031 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+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x64/0x198 arch/arm64/kernel/syscall.c:193 el0_svc+0x4c/0x15c 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 INFO: task syz-executor.4:2728 blocked for more than 143 seconds. Not tainted 6.4.0-rc2-syzkaller-gf1fcbaa18b28 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.4 state:D stack:0 pid:2728 ppid:6031 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 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_ioctl+0x128/0xc40 drivers/block/nbd.c:1521 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+0x4c/0x15c 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/13: #0: ffff8000160810d0 (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: ffff800016081490 (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: ffff800016080f00 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:326 2 locks held by getty/5735: #0: ffff0000db042098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340 #1: ffff80001adf02f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x414/0x1210 drivers/tty/n_tty.c:2176 1 lock held by udevd/15496: #0: ffff0000cd9af4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x12c/0x8f8 block/bdev.c:747 1 lock held by syz-executor.4/2711: #0: ffff0000cd9bb198 (&nbd->config_lock){+.+.}-{3:3}, at: nbd_start_device_ioctl drivers/block/nbd.c:1427 [inline] #0: ffff0000cd9bb198 (&nbd->config_lock){+.+.}-{3:3}, at: __nbd_ioctl drivers/block/nbd.c:1488 [inline] #0: ffff0000cd9bb198 (&nbd->config_lock){+.+.}-{3:3}, at: nbd_ioctl+0x8e8/0xc40 drivers/block/nbd.c:1528 1 lock held by syz-executor.4/2719: #0: ffff0000cd9af4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x12c/0x8f8 block/bdev.c:747 1 lock held by syz-executor.4/2723: #0: ffff0000cd9bb198 (&nbd->config_lock){+.+.}-{3:3}, at: nbd_ioctl+0x128/0xc40 drivers/block/nbd.c:1521 1 lock held by syz-executor.4/2728: #0: ffff0000cd9bb198 (&nbd->config_lock){+.+.}-{3:3}, at: nbd_ioctl+0x128/0xc40 drivers/block/nbd.c:1521 1 lock held by syz-executor.4/2869: #0: ffff0000cd9af4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x12c/0x8f8 block/bdev.c:747 1 lock held by syz-executor.4/2870: #0: ffff0000cd9af4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x12c/0x8f8 block/bdev.c:747 1 lock held by syz-executor.4/2871: #0: ffff0000cd9af4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x12c/0x8f8 block/bdev.c:747 1 lock held by syz-executor.4/2998: #0: ffff0000cd9af4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x12c/0x8f8 block/bdev.c:747 1 lock held by syz-executor.4/2999: #0: ffff0000cd9af4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x12c/0x8f8 block/bdev.c:747 1 lock held by syz-executor.4/3000: #0: ffff0000cd9af4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x12c/0x8f8 block/bdev.c:747 =============================================