syzbot

INFO: task syz-executor311:4040 blocked for more than 143 seconds.
      Not tainted 5.15.179-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor311 state:D stack:    0 pid: 4040 ppid:  4036 flags:0x0000000d
Call trace:
 __switch_to+0x308/0x588 arch/arm64/kernel/process.c:518
 context_switch kernel/sched/core.c:5029 [inline]
 __schedule+0xf10/0x1e48 kernel/sched/core.c:6375
 schedule+0x11c/0x1c8 kernel/sched/core.c:6458
 schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:6517
 __mutex_lock_common+0xba0/0x2154 kernel/locking/mutex.c:669
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0xa4/0xf8 kernel/locking/mutex.c:743
 bfs_lookup+0x11c/0x228 fs/bfs/dir.c:136
 __lookup_slow+0x250/0x388 fs/namei.c:1663
 lookup_slow+0x60/0x84 fs/namei.c:1680
 walk_component+0x394/0x4cc fs/namei.c:1976
 link_path_walk+0x5a0/0xc38 fs/namei.c:-1
 path_parentat fs/namei.c:2502 [inline]
 __filename_parentat+0x1d4/0x5b8 fs/namei.c:2526
 filename_parentat fs/namei.c:2544 [inline]
 filename_create+0xf0/0x468 fs/namei.c:3816
 do_mkdirat+0xac/0x610 fs/namei.c:4080
 __do_sys_mkdirat fs/namei.c:4105 [inline]
 __se_sys_mkdirat fs/namei.c:4103 [inline]
 __arm64_sys_mkdirat+0x90/0xa8 fs/namei.c:4103
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffff800014d41b60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:311
2 locks held by getty/3786:
 #0: ffff0000d3937098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x40/0x50 drivers/tty/tty_ldsem.c:340
 #1: ffff80001d6ce2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x414/0x1204 drivers/tty/n_tty.c:2158
3 locks held by syz-executor311/4038:
2 locks held by syz-executor311/4040:
 #0: ffff0000debc8168 (&type->i_mutex_dir_key#6){.+.+}-{3:3}, at: inode_lock_shared include/linux/fs.h:797 [inline]
 #0: ffff0000debc8168 (&type->i_mutex_dir_key#6){.+.+}-{3:3}, at: lookup_slow+0x50/0x84 fs/namei.c:1679
 #1: ffff0000c9a550d8 (&info->bfs_lock){+.+.}-{3:3}, at: bfs_lookup+0x11c/0x228 fs/bfs/dir.c:136

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