Re: [syzbot] [jfs?] UBSAN: array-index-out-of-bounds in dbSplit

[syzbot <syzbot+dca05492eff41f604890@syzkaller.appspotmail.com>]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
UBSAN: array-index-out-of-bounds in dbSplit

loop0: detected capacity change from 0 to 32768
loop0: detected capacity change from 32768 to 32745
------------[ cut here ]------------
UBSAN: array-index-out-of-bounds in fs/jfs/jfs_dmap.c:2629:27
index 4294967295 is out of range for type 's8[1365]' (aka 'signed char[1365]')
CPU: 1 PID: 5951 Comm: syz.0.15 Not tainted 6.10.0-syzkaller-11323-g7846b618e0a4-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 ubsan_epilogue lib/ubsan.c:231 [inline]
 __ubsan_handle_out_of_bounds+0x121/0x150 lib/ubsan.c:429
 dbSplit+0x1fd/0x220 fs/jfs/jfs_dmap.c:2629
 dbAllocBits+0x4e5/0x9a0 fs/jfs/jfs_dmap.c:2192
 dbAllocDmap fs/jfs/jfs_dmap.c:2033 [inline]
 dbAllocDmapLev+0x250/0x4a0 fs/jfs/jfs_dmap.c:1987
 dbAllocCtl+0x113/0x920 fs/jfs/jfs_dmap.c:1823
 dbAllocAG+0x28f/0x10b0 fs/jfs/jfs_dmap.c:1364
 dbAlloc+0x658/0xca0 fs/jfs/jfs_dmap.c:888
 dtSplitUp fs/jfs/jfs_dtree.c:979 [inline]
 dtInsert+0xda7/0x6b00 fs/jfs/jfs_dtree.c:868
 jfs_create+0x7ba/0xbb0 fs/jfs/namei.c:137
 lookup_open fs/namei.c:3578 [inline]
 open_last_lookups fs/namei.c:3647 [inline]
 path_openat+0x1a9a/0x3470 fs/namei.c:3883
 do_filp_open+0x235/0x490 fs/namei.c:3913
 do_sys_openat2+0x13e/0x1d0 fs/open.c:1416
 do_sys_open fs/open.c:1431 [inline]
 __do_sys_openat fs/open.c:1447 [inline]
 __se_sys_openat fs/open.c:1442 [inline]
 __x64_sys_openat+0x247/0x2a0 fs/open.c:1442
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3b4dd75b59
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:00007f3b4ebb0048 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f3b4df05f60 RCX: 00007f3b4dd75b59
RDX: 000000000000275a RSI: 0000000020000080 RDI: ffffffffffffff9c
RBP: 00007f3b4dde4e5d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f3b4df05f60 R15: 00007ffda143f618
 </TASK>
---[ end trace ]---


Tested on:

commit:         7846b618 Merge tag 'rtc-6.11' of git://git.kernel.org/..
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=16d89903980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=f4925140c45a2a50
dashboard link: https://syzkaller.appspot.com/bug?extid=dca05492eff41f604890
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=176745f1980000