[v5.15] WARNING: locking bug in gfs2_quotad

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 68efe5a6c16a Linux 5.15.197
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1257ddb4580000
kernel config: https://syzkaller.appspot.com/x/.config?x=7e6ed99963d6ee1d
dashboard link: https://syzkaller.appspot.com/bug?extid=c959474fb910550349ef
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/900f9b9bd850/disk-68efe5a6.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/1e089a5019a6/vmlinux-68efe5a6.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b319f477b907/bzImage-68efe5a6.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c95947...@syzkaller.appspotmail.com

------------[ cut here ]------------
DEBUG_LOCKS_WARN_ON(1)
WARNING: CPU: 1 PID: 4668 at kernel/locking/lockdep.c:201 hlock_class kernel/locking/lockdep.c:-1 [inline]
WARNING: CPU: 1 PID: 4668 at kernel/locking/lockdep.c:201 check_wait_context kernel/locking/lockdep.c:4686 [inline]
WARNING: CPU: 1 PID: 4668 at kernel/locking/lockdep.c:201 __lock_acquire+0x7cd/0x7c60 kernel/locking/lockdep.c:4962
Modules linked in:
CPU: 1 PID: 4668 Comm: gfs2_quotad Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:hlock_class kernel/locking/lockdep.c:201 [inline]
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4686 [inline]
RIP: 0010:__lock_acquire+0x7cd/0x7c60 kernel/locking/lockdep.c:4962
Code: 83 3d 7e 62 0d 0c 00 0f 85 c7 fd ff ff 48 c7 c7 80 1a 0b 8a 48 c7 c6 20 1d 0b 8a e8 0d 21 3b 08 48 ba 00 00 00 00 00 fc ff df <0f> 0b e9 a3 fd ff ff e8 47 ad 7b 02 85 c0 0f 84 5c 0a 00 00 48 c7
RSP: 0018:ffffc9000437f900 EFLAGS: 00010046
RAX: 163094e0fd219b00 RBX: 0000000000001309 RCX: ffff88807f0e8000
RDX: dffffc0000000000 RSI: 0000000080000001 RDI: 0000000000000000
RBP: ffffc9000437fb50 R08: dffffc0000000000 R09: fffff5200086fe85
R10: fffff5200086fe85 R11: 1ffff9200086fe84 R12: ffff88807f0e8b10
R13: ffff88807f0e8000 R14: 0000000000000000 R15: ffff88807f0e8af0
FS: 0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000000002c8 CR3: 0000000060c9c000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xa4/0xf0 kernel/locking/spinlock.c:162
finish_wait+0xb5/0x1d0 kernel/sched/wait.c:407
gfs2_quotad+0x703/0x880 fs/gfs2/quota.c:1605
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
</TASK>


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