[v6.1] UBSAN: array-index-out-of-bounds in xtTruncate

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: fb2635ac69ab Linux 6.1.62
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=11aa58b7680000
kernel config: https://syzkaller.appspot.com/x/.config?x=d1540e3da5e5623f
dashboard link: https://syzkaller.appspot.com/bug?extid=1e8cfd9e5b277fd19cf5
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/1bcbea336c80/disk-fb2635ac.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/859797d77ed0/vmlinux-fb2635ac.xz
kernel image: https://storage.googleapis.com/syzbot-assets/acd7a084757b/bzImage-fb2635ac.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+1e8cfd...@syzkaller.appspotmail.com

================================================================================
UBSAN: array-index-out-of-bounds in fs/jfs/jfs_xtree.c:2304:9
index 19 is out of range for type 'xad_t[18]' (aka 'struct xad[18]')
CPU: 1 PID: 23802 Comm: syz-executor.5 Not tainted 6.1.62-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
ubsan_epilogue lib/ubsan.c:151 [inline]
__ubsan_handle_out_of_bounds+0x118/0x140 lib/ubsan.c:282
xtTruncate+0x2730/0x3260 fs/jfs/jfs_xtree.c:2304
jfs_truncate_nolock+0x184/0x380 fs/jfs/inode.c:393
jfs_truncate+0xc7/0x140 fs/jfs/inode.c:417
jfs_setattr+0x603/0x840 fs/jfs/file.c:119
notify_change+0xce3/0xfc0 fs/attr.c:499
do_truncate+0x21c/0x300 fs/open.c:65
handle_truncate fs/namei.c:3217 [inline]
do_open fs/namei.c:3562 [inline]
path_openat+0x27e2/0x2e60 fs/namei.c:3715
do_filp_open+0x230/0x480 fs/namei.c:3742
do_sys_openat2+0x13b/0x500 fs/open.c:1318
do_sys_open fs/open.c:1334 [inline]
__do_sys_creat fs/open.c:1410 [inline]
__se_sys_creat fs/open.c:1404 [inline]
__x64_sys_creat+0x11f/0x160 fs/open.c:1404
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f821cc7cae9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f821d9e90c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 00007f821cd9c120 RCX: 00007f821cc7cae9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000040
RBP: 00007f821ccc847a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007f821cd9c120 R15: 00007ffcc11505b8
</TASK>
================================================================================


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.