[v6.1] kernel BUG in ocfs2_reserve_suballoc_bits (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 28c695c365e1 Linux 6.1.150
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=112bf962580000
kernel config: https://syzkaller.appspot.com/x/.config?x=68aa5a3af1cb953a
dashboard link: https://syzkaller.appspot.com/bug?extid=487e39304129321dd253
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
userspace arch: arm64

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/16e807247bf6/disk-28c695c3.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a2c735eaf8f9/vmlinux-28c695c3.xz
kernel image: https://storage.googleapis.com/syzbot-assets/080f0096d6c9/Image-28c695c3.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+487e39...@syzkaller.appspotmail.com

ocfs2: Mounting device (7,2) on (node local, slot 0) with writeback data mode.
------------[ cut here ]------------
kernel BUG at fs/ocfs2/suballoc.c:800!
Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP
Modules linked in:
CPU: 1 PID: 5047 Comm: syz.2.143 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/30/2025
pstate: 62400005 (nZCv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--)
pc : ocfs2_reserve_suballoc_bits+0x327c/0x3cd4 fs/ocfs2/suballoc.c:800
lr : ocfs2_reserve_suballoc_bits+0x327c/0x3cd4 fs/ocfs2/suballoc.c:800
sp : ffff8000215161c0
x29: ffff800021516640 x28: ffff0000d2215300 x27: ffff0000d2215310
x26: ffff7000042a2c60 x25: 00000000ffffffff x24: 000000000000ffff
x23: 0000000000000001 x22: ffff0000f73e1e00 x21: dfff800000000000
x20: 0000000000000000 x19: 0000000000000001 x18: ffff800011abbcc0
x17: 1fffe00033edbb7e x16: ffff8000082e7b10 x15: 0000000000000002
x14: 000000001195710c x13: 1ffff00002a180b1 x12: 0000000000080000
x11: 000000000007ffff x10: ffff800028e7a000 x9 : ffff800009db3680
x8 : 0000000000080000 x7 : ffff800009d46f10 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000001 x3 : ffff800011a318fc
x2 : 0000000000000000 x1 : 00000000ffffffff x0 : 0000000000000000
Call trace:
ocfs2_reserve_suballoc_bits+0x327c/0x3cd4 fs/ocfs2/suballoc.c:800
ocfs2_reserve_cluster_bitmap_bits fs/ocfs2/suballoc.c:1128 [inline]
ocfs2_reserve_clusters_with_limit+0x290/0x9e0 fs/ocfs2/suballoc.c:1173
ocfs2_reserve_clusters fs/ocfs2/suballoc.c:1223 [inline]
ocfs2_lock_allocators+0x27c/0x518 fs/ocfs2/suballoc.c:2669
ocfs2_write_begin_nolock+0x1d08/0x3ab4 fs/ocfs2/aops.c:1740
ocfs2_dio_wr_get_block+0x75c/0x14e0 fs/ocfs2/aops.c:2239
get_more_blocks fs/direct-io.c:665 [inline]
do_direct_IO fs/direct-io.c:953 [inline]
__blockdev_direct_IO+0x112c/0x318c fs/direct-io.c:1266
ocfs2_direct_IO+0x208/0x280 fs/ocfs2/aops.c:2468
generic_file_direct_write+0x31c/0x620 mm/filemap.c:3770
__generic_file_write_iter+0x1bc/0x37c mm/filemap.c:3930
ocfs2_file_write_iter+0x1300/0x1bf4 fs/ocfs2/file.c:2469
call_write_iter include/linux/fs.h:2265 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x5ac/0x7c4 fs/read_write.c:584
ksys_write+0x120/0x210 fs/read_write.c:637
__do_sys_write fs/read_write.c:649 [inline]
__se_sys_write fs/read_write.c:646 [inline]
__arm64_sys_write+0x7c/0x90 fs/read_write.c:646
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2bc arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
do_el0_svc+0x58/0x13c arch/arm64/kernel/syscall.c:204
el0_svc+0x58/0x138 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585
Code: 54ff1a8b 97ac8cf3 17fff8d2 979bb92f (d4210000)
---[ end trace 0000000000000000 ]---


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