option from the mount to silence this warning. ======================================================= ocfs2: Mounting device (7,0) on (node local, slot 0) with writeback data mode. ------------[ cut here ]------------ UBSAN: array-index-out-of-bounds in fs/ocfs2/suballoc.c:1447:7 index 1 is out of range for type 'struct ocfs2_chain_rec[] __counted_by(cl_count)' (aka 'struct ocfs2_chain_rec[]') CPU: 1 UID: 0 PID: 6051 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: 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_find_victim_chain fs/ocfs2/suballoc.c:1447 [inline] ocfs2_claim_suballoc_bits+0x8b6/0x1df0 fs/ocfs2/suballoc.c:1996 ocfs2_claim_metadata+0x178/0x4c0 fs/ocfs2/suballoc.c:2082 ocfs2_dx_dir_attach_index+0x1c1/0xd90 fs/ocfs2/dir.c:2341 ocfs2_expand_inline_dir fs/ocfs2/dir.c:3033 [inline] ocfs2_extend_dir+0x3994/0x4870 fs/ocfs2/dir.c:3215 ocfs2_prepare_dir_for_insert+0x2fdf/0x5550 fs/ocfs2/dir.c:4325 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: 0033:0x7fca0ff8d717 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:00007fffb6642738 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007fffb66427c0 RCX: 00007fca0ff8d717 RDX: 00000000000001ff RSI: 0000200000000680 RDI: 00000000ffffff9c RBP: 0000200000000080 R08: 0000200000000140 R09: 0000000000000000 R10: 0000200000000080 R11: 0000000000000246 R12: 0000200000000680 R13: 00007fffb6642780 R14: 0000000000000000 R15: 0000000000000000 ---[ end trace ]---