[v5.15] kernel BUG in ocfs2_reserve_suballoc_bits (2)

[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=174b348a580000
kernel config: https://syzkaller.appspot.com/x/.config?x=7e6ed99963d6ee1d
dashboard link: https://syzkaller.appspot.com/bug?extid=281540817de0eeb71fea
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+281540...@syzkaller.appspotmail.com

------------[ cut here ]------------
kernel BUG at fs/ocfs2/suballoc.c:800!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 4525 Comm: syz.1.44 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:ocfs2_reserve_suballoc_bits+0x3c3f/0x4350 fs/ocfs2/suballoc.c:800
Code: 00 00 e9 27 f3 ff ff 44 89 f1 80 e1 07 80 c1 03 38 c1 0f 8c 4b df ff ff 4c 89 f7 e8 0b 9a 9a fe e9 3e df ff ff e8 01 31 56 fe <0f> 0b 44 89 e1 80 e1 07 80 c1 03 38 c1 0f 8c e6 e0 ff ff 4c 89 e7
RSP: 0018:ffffc9000308e860 EFLAGS: 00010283
RAX: ffffffff83219b0f RBX: ffff88805616ae00 RCX: 0000000000080000
RDX: ffffc9000d359000 RSI: 0000000000003f6f RDI: 0000000000003f70
RBP: ffffc9000308ed30 R08: dffffc0000000000 R09: fffffbfff1ad26b6
R10: fffffbfff1ad26b6 R11: 1ffffffff1ad26b5 R12: 0000000000000000
R13: dffffc0000000000 R14: ffff8880743a4fb8 R15: 0000000000000001
FS: 00007f2da2b6f6c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2da2b4cfe0 CR3: 000000007b264000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
ocfs2_reserve_cluster_bitmap_bits fs/ocfs2/suballoc.c:1128 [inline]
ocfs2_reserve_clusters_with_limit+0x2f8/0xba0 fs/ocfs2/suballoc.c:1173
ocfs2_convert_inline_data_to_extents+0x1c6/0x11f0 fs/ocfs2/alloc.c:7072
ocfs2_try_to_write_inline_data fs/ocfs2/aops.c:1564 [inline]
ocfs2_write_begin_nolock+0x174d/0x4180 fs/ocfs2/aops.c:1671
ocfs2_write_begin+0x1ab/0x300 fs/ocfs2/aops.c:1905
generic_perform_write+0x2aa/0x530 mm/filemap.c:3785
__generic_file_write_iter+0x25f/0x4e0 mm/filemap.c:3912
ocfs2_file_write_iter+0x1578/0x1cf0 fs/ocfs2/file.c:2472
call_write_iter include/linux/fs.h:2173 [inline]
new_sync_write fs/read_write.c:507 [inline]
vfs_write+0x712/0xd00 fs/read_write.c:594
ksys_pwrite64 fs/read_write.c:701 [inline]
__do_sys_pwrite64 fs/read_write.c:711 [inline]
__se_sys_pwrite64 fs/read_write.c:708 [inline]
__x64_sys_pwrite64+0x194/0x220 fs/read_write.c:708
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f2da4929749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2da2b6f038 EFLAGS: 00000246 ORIG_RAX: 0000000000000012
RAX: ffffffffffffffda RBX: 00007f2da4b80090 RCX: 00007f2da4929749
RDX: 00000000ffffff07 RSI: 0000200000000140 RDI: 0000000000000004
RBP: 00007f2da49adf91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000008000c61 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2da4b80128 R14: 00007f2da4b80090 R15: 00007fffff7d5408
</TASK>
Modules linked in:
---[ end trace 6ea79c0eaa1f1659 ]---
RIP: 0010:ocfs2_reserve_suballoc_bits+0x3c3f/0x4350 fs/ocfs2/suballoc.c:800
Code: 00 00 e9 27 f3 ff ff 44 89 f1 80 e1 07 80 c1 03 38 c1 0f 8c 4b df ff ff 4c 89 f7 e8 0b 9a 9a fe e9 3e df ff ff e8 01 31 56 fe <0f> 0b 44 89 e1 80 e1 07 80 c1 03 38 c1 0f 8c e6 e0 ff ff 4c 89 e7
RSP: 0018:ffffc9000308e860 EFLAGS: 00010283
RAX: ffffffff83219b0f RBX: ffff88805616ae00 RCX: 0000000000080000
RDX: ffffc9000d359000 RSI: 0000000000003f6f RDI: 0000000000003f70
RBP: ffffc9000308ed30 R08: dffffc0000000000 R09: fffffbfff1ad26b6
R10: fffffbfff1ad26b6 R11: 1ffffffff1ad26b5 R12: 0000000000000000
R13: dffffc0000000000 R14: ffff8880743a4fb8 R15: 0000000000000001
FS: 00007f2da2b6f6c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c410c97 CR3: 000000007b264000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


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