[v6.1] WARNING in do_loopback

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 81e1dc2f7001 Linux 6.1.79
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1768aca2180000
kernel config: https://syzkaller.appspot.com/x/.config?x=1f1b2df4155f9cc0
dashboard link: https://syzkaller.appspot.com/bug?extid=5ac59587cd99810d2319
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/c15e68f002df/disk-81e1dc2f.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/48d036ef2f3c/vmlinux-81e1dc2f.xz
kernel image: https://storage.googleapis.com/syzbot-assets/f372bf435776/bzImage-81e1dc2f.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+5ac595...@syzkaller.appspotmail.com

------------[ cut here ]------------
DEBUG_RWSEMS_WARN_ON((rwsem_owner(sem) != current) && !rwsem_test_oflags(sem, RWSEM_NONSPINNABLE)): count = 0x0, magic = 0xffff88808a198a90, owner = 0x0, curr 0xffff888082323b80, list empty
WARNING: CPU: 1 PID: 12489 at kernel/locking/rwsem.c:1372 __up_write kernel/locking/rwsem.c:1371 [inline]
WARNING: CPU: 1 PID: 12489 at kernel/locking/rwsem.c:1372 up_write+0x4f5/0x580 kernel/locking/rwsem.c:1626
Modules linked in:
CPU: 1 PID: 12489 Comm: syz-executor.1 Not tainted 6.1.79-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
RIP: 0010:__up_write kernel/locking/rwsem.c:1371 [inline]
RIP: 0010:up_write+0x4f5/0x580 kernel/locking/rwsem.c:1626
Code: 48 c7 c7 e0 e0 eb 8a 48 c7 c6 20 e3 eb 8a 48 8b 54 24 28 48 8b 4c 24 18 4d 89 e0 4c 8b 4c 24 30 53 e8 ff db e8 ff 48 83 c4 08 <0f> 0b e9 71 fd ff ff 48 c7 c1 e8 7a 73 8e 80 e1 07 80 c1 03 38 c1
RSP: 0018:ffffc90013b47ca0 EFLAGS: 00010296
RAX: be3a07536f4da200 RBX: ffffffff8aebe1c0 RCX: 0000000000040000
RDX: ffffc900059b9000 RSI: 000000000000a6a6 RDI: 000000000000a6a7
RBP: ffffc90013b47d70 R08: ffffffff81527e8e R09: fffff52002768f35
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000
R13: ffff88808a198a90 R14: 1ffff92002768f9c R15: dffffc0000000000
FS: 00007f98db9dd6c0(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000004e4b6000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
inode_unlock include/linux/fs.h:761 [inline]
unlock_mount fs/namespace.c:2325 [inline]
do_loopback+0x4a5/0x510 fs/namespace.c:2459
do_mount fs/namespace.c:3394 [inline]
__do_sys_mount fs/namespace.c:3602 [inline]
__se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3579
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f98dce7dda9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f98db9dd0c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f98dcfac050 RCX: 00007f98dce7dda9
RDX: 0000000000000000 RSI: 0000000020000200 RDI: 00000000200002c0
RBP: 00007f98dceca47a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000101091 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007f98dcfac050 R15: 00007ffe32995558
</TASK>


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup