[v6.6] UBSAN: array-index-out-of-bounds in add_missing_indices

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 3f5b4c104b7d Linux 6.6.95
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=104573d4580000
kernel config: https://syzkaller.appspot.com/x/.config?x=747dbf84b0ecd30c
dashboard link: https://syzkaller.appspot.com/bug?extid=34272791bb194e2b8b24
compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/421f6e2d0cd1/disk-3f5b4c10.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/90250695b20b/vmlinux-3f5b4c10.xz
kernel image: https://storage.googleapis.com/syzbot-assets/32250e77bce9/bzImage-3f5b4c10.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+342727...@syzkaller.appspotmail.com

================================================================================
UBSAN: array-index-out-of-bounds in fs/jfs/jfs_dtree.c:2650:28
index -128 is out of range for type 'struct dtslot[128]'
CPU: 1 PID: 10733 Comm: syz.0.1077 Not tainted 6.6.95-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
<TASK>
dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
ubsan_epilogue+0xa/0x30 lib/ubsan.c:217
__ubsan_handle_out_of_bounds+0xe3/0xf0 lib/ubsan.c:348
add_missing_indices+0x6a0/0xbb0 fs/jfs/jfs_dtree.c:2650
jfs_readdir+0x1d80/0x3a90 fs/jfs/jfs_dtree.c:3020
wrap_directory_iterator+0x92/0xd0 fs/readdir.c:67
iterate_dir+0x1c2/0x580 fs/readdir.c:106
__do_sys_getdents64 fs/readdir.c:405 [inline]
__se_sys_getdents64+0xe9/0x260 fs/readdir.c:390
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f1d61f8e929
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:00007f1d62d9b038 EFLAGS: 00000246 ORIG_RAX: 00000000000000d9
RAX: ffffffffffffffda RBX: 00007f1d621b5fa0 RCX: 00007f1d61f8e929
RDX: 00000000000006e6 RSI: 0000200000001c80 RDI: 0000000000000005
RBP: 00007f1d62010b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f1d621b5fa0 R15: 00007ffcd6cdb348
</TASK>
================================================================================


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: 60a9e718726f Linux 6.6.106
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=120b8f62580000
kernel config: https://syzkaller.appspot.com/x/.config?x=12606d4b8832c7e4
dashboard link: https://syzkaller.appspot.com/bug?extid=34272791bb194e2b8b24
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10f0cc7c580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=142f6f62580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/eca27e056a5a/disk-60a9e718.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/bc64d4eeb7f6/vmlinux-60a9e718.xz
kernel image: https://storage.googleapis.com/syzbot-assets/a345041561ac/bzImage-60a9e718.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/4cde5134e356/mount_0.gz
fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=1770cc7c580000)

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+342727...@syzkaller.appspotmail.com

... Log Wrap ... Log Wrap ... Log Wrap ...
... Log Wrap ... Log Wrap ... Log Wrap ...

================================================================================
UBSAN: array-index-out-of-bounds in fs/jfs/jfs_dtree.c:2650:28
index -128 is out of range for type 'struct dtslot[128]'

CPU: 0 PID: 5943 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025

Call Trace:
<TASK>
dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
ubsan_epilogue+0xa/0x30 lib/ubsan.c:217
__ubsan_handle_out_of_bounds+0xe3/0xf0 lib/ubsan.c:348
add_missing_indices+0x6a0/0xbb0 fs/jfs/jfs_dtree.c:2650
jfs_readdir+0x1d80/0x3a90 fs/jfs/jfs_dtree.c:3020
wrap_directory_iterator+0x92/0xd0 fs/readdir.c:67
iterate_dir+0x1c2/0x580 fs/readdir.c:106
__do_sys_getdents64 fs/readdir.c:405 [inline]
__se_sys_getdents64+0xe9/0x260 fs/readdir.c:390
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2

RIP: 0033:0x7f471318eba9

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:00007ffd5324ab98 EFLAGS: 00000246 ORIG_RAX: 00000000000000d9
RAX: ffffffffffffffda RBX: 00007f47133d5fa0 RCX: 00007f471318eba9
RDX: 0000000000000037 RSI: 00002000000000c0 RDI: 0000000000000005
RBP: 00007f4713211e19 R08: 0000000000000000 R09: 0000000000000000

R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000

R13: 00007f47133d5fa0 R14: 00007f47133d5fa0 R15: 0000000000000003
</TASK>
================================================================================


---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.