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

[syzbot <syzbot+c1056fdfe414463fdb33@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 diWrite

diWrite: Offset too large
================================================================================
UBSAN: array-index-out-of-bounds in fs/jfs/jfs_imap.c:754:4
index 255 is out of range for type 'struct dtslot[128]'
CPU: 1 PID: 5407 Comm: syz-executor.0 Not tainted 6.6.0-syzkaller-10396-g4652b8e4f3ff-dirty #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+0x1b5/0x2a0 lib/dump_stack.c:106
 ubsan_epilogue lib/ubsan.c:217 [inline]
 __ubsan_handle_out_of_bounds+0xf0/0x120 lib/ubsan.c:348
 diWrite+0x1168/0x2060 fs/jfs/jfs_imap.c:754
 txCommit+0xa03/0x6a00 fs/jfs/jfs_txnmgr.c:1255
 jfs_mkdir+0x8d7/0xad0 fs/jfs/namei.c:290
 vfs_mkdir+0x2f1/0x4b0 fs/namei.c:4106
 do_mkdirat+0x255/0x390 fs/namei.c:4129
 __do_sys_mkdirat fs/namei.c:4144 [inline]
 __se_sys_mkdirat fs/namei.c:4142 [inline]
 __x64_sys_mkdirat+0x89/0xa0 fs/namei.c:4142
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7fa34307ad39
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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fa3441290c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007fa34319bf80 RCX: 00007fa34307ad39
RDX: 00000000000001ff RSI: 00000000200000c0 RDI: ffffffffffffff9c
RBP: 00007fa3430d7567 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007fa34319bf80 R15: 00007ffd3c0fbd48
 </TASK>
================================================================================


Tested on:

commit:         4652b8e4 Merge tag '6.7-rc-ksmbd-server-fixes' of git:..
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
console output: https://syzkaller.appspot.com/x/log.txt?x=15fb1f07680000
kernel config:  https://syzkaller.appspot.com/x/.config?x=8aa5f62c74d2e2d5
dashboard link: https://syzkaller.appspot.com/bug?extid=c1056fdfe414463fdb33
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=10e93ef7680000