INFO: task udevd:3156 blocked for more than 430 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:0 pid:3156 tgid:3156 ppid:1 task_flags:0x400140 flags:0x00000000 Call trace: __switch_to+0x20c/0x520 arch/arm64/kernel/process.c:810 (T) context_switch kernel/sched/core.c:5387 [inline] __schedule+0xd3c/0x3494 kernel/sched/core.c:7188 __schedule_loop kernel/sched/core.c:7267 [inline] schedule+0xcc/0x348 kernel/sched/core.c:7282 schedule_preempt_disabled+0x18/0x38 kernel/sched/core.c:7339 __mutex_lock_common kernel/locking/mutex.c:712 [inline] __mutex_lock+0x7e8/0x14dc kernel/locking/mutex.c:806 mutex_lock_nested+0x24/0x30 kernel/locking/mutex.c:859 bdev_open+0x2b8/0xa70 block/bdev.c:953 blkdev_open+0x270/0x3f0 block/fops.c:697 do_dentry_open+0x388/0x10e4 fs/open.c:947 vfs_open+0x5c/0x2fc fs/open.c:1079 do_open fs/namei.c:4699 [inline] path_openat+0x1734/0x2654 fs/namei.c:4858 do_file_open+0x18c/0x37c fs/namei.c:4887 do_sys_openat2+0xdc/0x184 fs/open.c:1364 do_sys_open fs/open.c:1370 [inline] __do_sys_openat fs/open.c:1386 [inline] __se_sys_openat fs/open.c:1381 [inline] __arm64_sys_openat+0x130/0x1d0 fs/open.c:1381 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x74/0x240 arch/arm64/kernel/syscall.c:49 el0_svc_common.constprop.0+0xac/0x230 arch/arm64/kernel/syscall.c:121 do_el0_svc+0x40/0x58 arch/arm64/kernel/syscall.c:140 el0_svc+0x58/0x2a4 arch/arm64/kernel/entry-common.c:723 el0t_64_sync_handler+0xa0/0xe4 arch/arm64/kernel/entry-common.c:742 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594 INFO: task syz-executor.0:3655 blocked for more than 430 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:0 pid:3655 tgid:3652 ppid:3540 task_flags:0x400140 flags:0x00000019 Call trace: __switch_to+0x20c/0x520 arch/arm64/kernel/process.c:810 (T) context_switch kernel/sched/core.c:5387 [inline] __schedule+0xd3c/0x3494 kernel/sched/core.c:7188 __schedule_loop kernel/sched/core.c:7267 [inline] schedule+0xcc/0x348 kernel/sched/core.c:7282 schedule_preempt_disabled+0x18/0x38 kernel/sched/core.c:7339 __mutex_lock_common kernel/locking/mutex.c:712 [inline] __mutex_lock+0x7e8/0x14dc kernel/locking/mutex.c:806 mutex_lock_nested+0x24/0x30 kernel/locking/mutex.c:859 bdev_release+0x104/0x510 block/bdev.c:1136 blkdev_release+0x14/0x24 block/fops.c:705 __fput+0x2d0/0x980 fs/file_table.c:510 ____fput+0x14/0x20 fs/file_table.c:538 task_work_run+0x134/0x238 kernel/task_work.c:233 get_signal+0x17c/0x1f0c kernel/signal.c:2809 arch_do_signal_or_restart+0x1a0/0x6c0 arch/arm64/kernel/signal.c:1633 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x140/0x1c8 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] exit_to_user_mode_prepare_legacy include/linux/irq-entry-common.h:224 [inline] arm64_exit_to_user_mode arch/arm64/kernel/entry-common.c:86 [inline] el0_svc+0x260/0x2a4 arch/arm64/kernel/entry-common.c:724 el0t_64_sync_handler+0xa0/0xe4 arch/arm64/kernel/entry-common.c:742 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594 Showing all locks held in the system: 2 locks held by kworker/u8:1/26: 1 lock held by khungtaskd/32: #0: ffff800087870460 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x30/0x198 kernel/locking/lockdep.c:6771 1 lock held by klogd/3145: 1 lock held by udevd/3156: #0: ffff000014ef6350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x2b8/0xa70 block/bdev.c:953 2 locks held by getty/3280: #0: ffff00000f5bd0a0 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340 #1: ffff80008dc6b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x420/0xec8 drivers/tty/n_tty.c:2211 1 lock held by syz-executor.0/3655: #0: ffff000014ef6350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x104/0x510 block/bdev.c:1136 1 lock held by udevd/3659: #0: ffff000014ef6350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x2b8/0xa70 block/bdev.c:953 1 lock held by syz-executor.0/3765: #0: ffff000014ef6350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x2b8/0xa70 block/bdev.c:953 1 lock held by syz-executor.0/3842: #0: ffff000014ef6350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x2b8/0xa70 block/bdev.c:953 =============================================