[v6.1] WARNING in hfsplus_ext_write_extent (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 8e6e2188d949 Linux 6.1.157
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=125a5734580000
kernel config: https://syzkaller.appspot.com/x/.config?x=7eb38bd5021fec61
dashboard link: https://syzkaller.appspot.com/bug?extid=45009b00c9c1b0c8af51
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/dcc01324de1b/disk-8e6e2188.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a93dd5469c70/vmlinux-8e6e2188.xz
kernel image: https://storage.googleapis.com/syzbot-assets/04635e384401/bzImage-8e6e2188.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+45009b...@syzkaller.appspotmail.com

------------[ cut here ]------------
DEBUG_LOCKS_WARN_ON(lock->magic != lock)
WARNING: CPU: 1 PID: 3391 at kernel/locking/mutex.c:582 __mutex_lock_common kernel/locking/mutex.c:582 [inline]
WARNING: CPU: 1 PID: 3391 at kernel/locking/mutex.c:582 __mutex_lock+0xa24/0xaf0 kernel/locking/mutex.c:747
Modules linked in:
CPU: 1 PID: 3391 Comm: kworker/u4:9 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Workqueue: writeback wb_workfn (flush-7:3)
RIP: 0010:__mutex_lock_common kernel/locking/mutex.c:582 [inline]
RIP: 0010:__mutex_lock+0xa24/0xaf0 kernel/locking/mutex.c:747
Code: 04 28 84 c0 0f 85 b7 00 00 00 83 3d 2d dc fe 03 00 0f 85 e0 f6 ff ff 48 c7 c7 00 f0 8b 8a 48 c7 c6 a0 f0 8b 8a e8 ec 35 2c f7 <0f> 0b e9 c6 f6 ff ff 0f 0b e9 6c f9 ff ff 48 c7 c1 40 91 be 96 80
RSP: 0018:ffffc90005347280 EFLAGS: 00010246
RAX: ae0f951b1b8ac700 RBX: ffff888071acd000 RCX: ffff88804b000000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000002
RBP: ffffc900053473d0 R08: dffffc0000000000 R09: ffffed10171e4f34
R10: ffffed10171e4f34 R11: 1ffff110171e4f33 R12: 0000000000000000
R13: dffffc0000000000 R14: 1ffff92000a68e80 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555638755c8 CR3: 0000000036e57000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
hfsplus_ext_write_extent+0x87/0x200 fs/hfsplus/extents.c:149
hfsplus_write_inode+0x1e/0x5b0 fs/hfsplus/super.c:154
write_inode fs/fs-writeback.c:1470 [inline]
__writeback_single_inode+0x75b/0x1160 fs/fs-writeback.c:1687
writeback_sb_inodes+0xad8/0x17d0 fs/fs-writeback.c:1913
wb_writeback+0x468/0xd00 fs/fs-writeback.c:2087
wb_do_writeback fs/fs-writeback.c:2230 [inline]
wb_workfn+0x435/0xec0 fs/fs-writeback.c:2270
process_one_work+0x898/0x1160 kernel/workqueue.c:2292
worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>


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