[v5.15] INFO: task hung in bfs_lookup

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 0c935c049b5c Linux 5.15.179
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=14307d98580000
kernel config: https://syzkaller.appspot.com/x/.config?x=98c228fbc016eb3a
dashboard link: https://syzkaller.appspot.com/bug?extid=9726a39347f9f98cfb37
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=153a523f980000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11313b4c580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/d5477072f336/disk-0c935c04.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/77d15907ffb3/vmlinux-0c935c04.xz
kernel image: https://storage.googleapis.com/syzbot-assets/efe5d79cb16a/Image-0c935c04.gz.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/2948986564e9/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9726a3...@syzkaller.appspotmail.com

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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