[v5.15] UBSAN: array-index-out-of-bounds in xtSearch

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 2ddbd0f967b3 Linux 5.15.102
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=109b5672c80000
kernel config: https://syzkaller.appspot.com/x/.config?x=fec083380faceb1e
dashboard link: https://syzkaller.appspot.com/bug?extid=1635aa86b9116b6efe07
compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/156d2aa91f3c/disk-2ddbd0f9.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/f0e97f5be5fb/vmlinux-2ddbd0f9.xz
kernel image: https://storage.googleapis.com/syzbot-assets/20d0a55a041d/bzImage-2ddbd0f9.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+1635aa...@syzkaller.appspotmail.com

UBSAN: array-index-out-of-bounds in fs/jfs/jfs_xtree.c:281:11
index 19 is out of range for type 'xad_t[18]' (aka 'struct xad[18]')
CPU: 0 PID: 4983 Comm: syz-executor.0 Not tainted 5.15.102-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023
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
xtSearch+0x10e8/0x1ca0 fs/jfs/jfs_xtree.c:281
xtLookup+0x2c0/0x8e0 fs/jfs/jfs_xtree.c:163
extHint+0x291/0x710 fs/jfs/jfs_extent.c:374
jfs_get_block+0x3a7/0xe50 fs/jfs/inode.c:256
nobh_write_begin+0x398/0xda0 fs/buffer.c:2650
jfs_write_begin+0x3e/0x80 fs/jfs/inode.c:322
generic_perform_write+0x2bf/0x5b0 mm/filemap.c:3776
__generic_file_write_iter+0x243/0x4f0 mm/filemap.c:3903
generic_file_write_iter+0xa7/0x1b0 mm/filemap.c:3935
call_write_iter include/linux/fs.h:2101 [inline]
new_sync_write fs/read_write.c:507 [inline]
vfs_write+0xacf/0xe50 fs/read_write.c:594
ksys_write+0x1a2/0x2c0 fs/read_write.c:647
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+0x61/0xcb
RIP: 0033:0x7fa9115350f9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fa90faa7168 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fa911654f80 RCX: 00007fa9115350f9
RDX: 000000000208e24b RSI: 0000000020000280 RDI: 0000000000000005
RBP: 00007fa911590b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffd9613642f R14: 00007fa90faa7300 R15: 0000000000022000
</TASK>
================================================================================


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[syzbot]

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