INFO: task syz.0.172 INFO: task syz.0.1724:10568 blocked for more than 145 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.1724 state:D stack:0 pid:10568 tgid:10564 ppid:4715 task_flags:0x400140 flags:0x00800001 Call trace: __switch_to+0x2b0/0x6e0 arch/arm64/kernel/process.c:810 (T) context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1c04/0x2db8 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0x13c/0x20c kernel/sched/core.c:7283 schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:7340 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0x4fc/0xed0 kernel/locking/mutex.c:820 mutex_lock_nested+0x24/0x30 kernel/locking/mutex.c:873 bdev_open+0xc4/0x880 block/bdev.c:953 blkdev_open+0x2d4/0x408 block/fops.c:697 do_dentry_open+0x5c4/0xfb8 fs/open.c:947 vfs_open+0x44/0x2dc fs/open.c:1079 do_open fs/namei.c:4699 [inline] path_openat+0x22d4/0x2b88 fs/namei.c:4858 do_file_open+0x1c8/0x2e8 fs/namei.c:4887 do_sys_openat2+0x114/0x1e8 fs/open.c:1364 do_sys_open+0xac/0xdc fs/open.c:1370 __do_sys_openat fs/open.c:1386 [inline] __se_sys_openat fs/open.c:1381 [inline] __arm64_sys_openat+0xa0/0xbc fs/open.c:1381 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:736 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:755 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffff800088bf70c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffff800088bf70c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffff800088bf70c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x4c/0x188 kernel/locking/lockdep.c:6775 2 locks held by kworker/u8:4/182: #0: ffff0000c004c140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline] #0: ffff0000c004c140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x734/0x10b8 kernel/workqueue.c:3397 #1: ffff800092557c40 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline] #1: ffff800092557c40 ((reaper_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x73c/0x10b8 kernel/workqueue.c:3397 2 locks held by getty/4491: #0: ffff0000cb5fd0a0 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340 #1: ffff8000923ab2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x348/0xf70 drivers/tty/n_tty.c:2211 1 lock held by udevd/7331: #0: ffff0000c8ba0350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xc4/0x880 block/bdev.c:953 1 lock held by udevd/7333: 1 lock held by syz.0.1724/10568: #0: ffff0000c8ba0350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xc4/0x880 block/bdev.c:953 2 locks held by syz.3.2870/15544: =============================================