syzbot
UBSAN: array-index-out-of-bounds in ocfs2_block_group_fill
Status:
fixed on 2026/01/07 12:29
Subsystems:
ocfs2
[Documentation on labels]
Reported-by: syzbot+77026564530dbc29b854@syzkaller.appspotmail.com
Fix commit:
e1c70505ee81
ocfs2: add extra consistency checks for chain allocator dinodes
First crash: 288d, last: 285d
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Last patch testing requests (18)
Sample crash report:
option from the mount to silence this warning.
=======================================================
JBD2: Ignoring recovery information on journal
ocfs2: Mounting device (7,0) on (node local, slot 0) with ordered data mode.
------------[ cut here ]------------
UBSAN: array-index-out-of-bounds in fs/ocfs2/suballoc.c:380:22
index 0 is out of range for type 'struct ocfs2_chain_rec[] __counted_by(cl_count)' (aka 'struct ocfs2_chain_rec[]')
CPU: 0 UID: 0 PID: 6052 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
<TASK>
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
ubsan_epilogue+0xa/0x40 lib/ubsan.c:233
__ubsan_handle_out_of_bounds+0xe9/0xf0 lib/ubsan.c:455
ocfs2_block_group_fill+0x938/0xb30 fs/ocfs2/suballoc.c:380
ocfs2_block_group_alloc_contig fs/ocfs2/suballoc.c:454 [inline]
ocfs2_block_group_alloc fs/ocfs2/suballoc.c:699 [inline]
ocfs2_reserve_suballoc_bits+0x117d/0x4680 fs/ocfs2/suballoc.c:834
ocfs2_reserve_new_metadata_blocks+0x403/0x940 fs/ocfs2/suballoc.c:984
ocfs2_expand_inline_dir fs/ocfs2/dir.c:2853 [inline]
ocfs2_extend_dir+0xc76/0x4870 fs/ocfs2/dir.c:3215
ocfs2_prepare_dir_for_insert+0x2fdf/0x54b0 fs/ocfs2/dir.c:4320
ocfs2_mknod+0x819/0x2050 fs/ocfs2/namei.c:297
ocfs2_mkdir+0x191/0x440 fs/ocfs2/namei.c:659
vfs_mkdir+0x306/0x510 fs/namei.c:4453
do_mkdirat+0x247/0x590 fs/namei.c:4486
__do_sys_mkdirat fs/namei.c:4503 [inline]
__se_sys_mkdirat fs/namei.c:4501 [inline]
__x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4501
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0917d8d617
Code: 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 02 01 00 00 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:00007fff863b0218 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007fff863b02a0 RCX: 00007f0917d8d617
RDX: 00000000000001ff RSI: 0000200000000680 RDI: 00000000ffffff9c
RBP: 0000200000000080 R08: 0000200000000140 R09: 0000000000000000
R10: 0000200000000080 R11: 0000000000000246 R12: 0000200000000680
R13: 00007fff863b0260 R14: 0000000000000000 R15: 0000000000000000
</TASK>
---[ end trace ]---
* Struck through repros no longer work on HEAD.