I
INFO: task syz-executor.0:4978 blocked for more than 143 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:4978  tgid:4978  ppid:4872   task_flags:0x400040 flags:0x00000001
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_release+0x128/0x328 block/bdev.c:1136
 blkdev_release+0x20/0x34 block/fops.c:705
 __fput+0x338/0x74c fs/file_table.c:510
 fput_close_sync+0x10c/0x278 fs/file_table.c:615
 __do_sys_close fs/open.c:1507 [inline]
 __se_sys_close fs/open.c:1492 [inline]
 __arm64_sys_close+0x7c/0x10c fs/open.c:1492
 __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 pr/ttyAMA-1/41:
2 locks held by getty/4491:
 #0: ffff0000d45cb0a0 (&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
2 locks held by kworker/0:4/4761:
1 lock held by udevd/4793:
 #0: ffff0000c8762350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xc4/0x880 block/bdev.c:953
1 lock held by syz-executor.0/4978:
 #0: ffff0000c8762350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x128/0x328 block/bdev.c:1136
1 lock held by syz-executor.0/5069:
 #0: ffff0000c8762350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xc4/0x880 block/bdev.c:953
1 lock held by syz-executor.0/5070:
 #0: ffff0000c8762350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xc4/0x880 block/bdev.c:953
1 lock held by syz-executor.0/5111:
 #0: ffff0000c8762350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xc4/0x880 block/bdev.c:953
1 lock held by syz-executor.0/5112:
 #0: ffff0000c8762350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xc4/0x880 block/bdev.c:953

=============================================