INFO: task udevd:6191 INFO: task udevd:6191 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:0 pid:6191 tgid:6191 ppid:1 task_flags:0x400140 flags:0x00800008 Call trace: __switch_to+0x418/0x87c arch/arm64/kernel/process.c:741 (T) context_switch kernel/sched/core.c:5325 [inline] __schedule+0x13b0/0x2864 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0xb4/0x230 kernel/sched/core.c:7026 schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:7083 __mutex_lock_common+0xd04/0x2678 kernel/locking/mutex.c:676 __mutex_lock kernel/locking/mutex.c:760 [inline] mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:812 bdev_open+0xcc/0xc20 block/bdev.c:945 blkdev_open+0x364/0x4e8 block/fops.c:701 do_dentry_open+0x7a4/0x10bc fs/open.c:965 vfs_open+0x44/0x2d4 fs/open.c:1097 do_open fs/namei.c:3975 [inline] path_openat+0x2424/0x2c40 fs/namei.c:4134 do_filp_open+0x18c/0x36c fs/namei.c:4161 do_sys_openat2+0x11c/0x1b4 fs/open.c:1437 do_sys_open fs/open.c:1452 [inline] __do_sys_openat fs/open.c:1468 [inline] __se_sys_openat fs/open.c:1463 [inline] __arm64_sys_openat+0x120/0x158 fs/open.c:1463 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x254 arch/arm64/kernel/syscall.c:49 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x5c/0x254 arch/arm64/kernel/entry-common.c:746 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:765 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596 INFO: task syz.0.17:6745 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.17 state:D stack:0 pid:6745 tgid:6745 ppid:6680 task_flags:0x400040 flags:0x00000001 Call trace: __switch_to+0x418/0x87c arch/arm64/kernel/process.c:741 (T) context_switch kernel/sched/core.c:5325 [inline] __schedule+0x13b0/0x2864 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0xb4/0x230 kernel/sched/core.c:7026 schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:7083 __mutex_lock_common+0xd04/0x2678 kernel/locking/mutex.c:676 __mutex_lock kernel/locking/mutex.c:760 [inline] mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:812 bdev_release+0x154/0x654 block/bdev.c:1128 blkdev_release+0x20/0x34 block/fops.c:709 __fput+0x340/0x75c fs/file_table.c:468 ____fput+0x20/0x58 fs/file_table.c:496 task_work_run+0x1dc/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xfc/0x178 kernel/entry/common.c:43 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] arm64_exit_to_user_mode arch/arm64/kernel/entry-common.c:103 [inline] el0_svc+0x170/0x254 arch/arm64/kernel/entry-common.c:747 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:765 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596 INFO: task syz.0.17:6746 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.17 state:D stack:0 pid:6746 tgid:6745 ppid:6680 task_flags:0x400140 flags:0x00000011 Call trace: __switch_to+0x418/0x87c arch/arm64/kernel/process.c:741 (T) context_switch kernel/sched/core.c:5325 [inline] __schedule+0x13b0/0x2864 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0xb4/0x230 kernel/sched/core.c:7026 schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:7083 __mutex_lock_common+0xd04/0x2678 kernel/locking/mutex.c:676 __mutex_lock kernel/locking/mutex.c:760 [inline] mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:812 bdev_release+0x154/0x654 block/bdev.c:1128 blkdev_release+0x20/0x34 block/fops.c:709 __fput+0x340/0x75c fs/file_table.c:468 ____fput+0x20/0x58 fs/file_table.c:496 task_work_run+0x1dc/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xfc/0x178 kernel/entry/common.c:43 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] arm64_exit_to_user_mode arch/arm64/kernel/entry-common.c:103 [inline] el0_svc+0x170/0x254 arch/arm64/kernel/entry-common.c:747 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:765 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596 Showing all locks held in the system: 1 lock held by khungtaskd/32: #0: ffff80008f76b5a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire+0x4/0x48 include/linux/rcupdate.h:330 2 locks held by pr/ttyAMA-1/43: 2 locks held by kworker/u8:5/933: 1 lock held by udevd/6191: #0: ffff0000ca673358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xcc/0xc20 block/bdev.c:945 2 locks held by getty/6334: #0: ffff0000d79820a0 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340 #1: ffff8000991842f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x34c/0xfa4 drivers/tty/n_tty.c:2222 2 locks held by kworker/u9:2/6622: #0: ffff0000ca69d148 ((wq_completion)nbd1-recv){+.+.}-{0:0}, at: process_one_work+0x63c/0x155c kernel/workqueue.c:3237 #1: ffff8000a4f07be0 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x6d4/0x155c kernel/workqueue.c:3237 1 lock held by udevd/6623: #0: ffff0000ca673358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xcc/0xc20 block/bdev.c:945 1 lock held by syz.0.17/6745: #0: ffff0000ca673358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x154/0x654 block/bdev.c:1128 1 lock held by syz.0.17/6746: #0: ffff0000ca673358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x154/0x654 block/bdev.c:1128 =============================================