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

[syzbot <syzbot+015483fc71d1413f40ee@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    7a0892d2836e Merge tag 'pci-v6.18-fixes-5' of git://git.ke..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1285760a580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=929790bc044e87d7
dashboard link: https://syzkaller.appspot.com/bug?extid=015483fc71d1413f40ee
compiler:       Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8

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

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-7a0892d2.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a78c5c2efd8d/vmlinux-7a0892d2.xz
kernel image: https://storage.googleapis.com/syzbot-assets/5a51cc5df960/bzImage-7a0892d2.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+015483fc71d1413f40ee@syzkaller.appspotmail.com

loop0: detected capacity change from 0 to 32768
netlink: 96 bytes leftover after parsing attributes in process `syz.0.0'.
------------[ cut here ]------------
UBSAN: array-index-out-of-bounds in fs/jfs/jfs_imap.c:2105:2
index 8592359 is out of range for type 'struct iagctl[128]'
CPU: 0 UID: 0 PID: 5318 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 ubsan_epilogue+0xa/0x40 lib/ubsan.c:233
 __ubsan_handle_out_of_bounds+0xe9/0xf0 lib/ubsan.c:455
 diAllocBit+0xba2/0xd40 fs/jfs/jfs_imap.c:2105
 diAllocIno fs/jfs/jfs_imap.c:1844 [inline]
 diAllocAG+0x12d9/0x1df0 fs/jfs/jfs_imap.c:1676
 diAlloc+0x1d5/0x1680 fs/jfs/jfs_imap.c:1590
 ialloc+0x8c/0x8f0 fs/jfs/jfs_inode.c:56
 jfs_create+0x18d/0xa80 fs/jfs/namei.c:92
 lookup_open fs/namei.c:3796 [inline]
 open_last_lookups fs/namei.c:3895 [inline]
 path_openat+0x14f4/0x3830 fs/namei.c:4131
 do_filp_open+0x1fa/0x410 fs/namei.c:4161
 do_sys_openat2+0x121/0x1c0 fs/open.c:1437
 do_sys_open fs/open.c:1452 [inline]
 __do_sys_openat fs/open.c:1468 [inline]
 __se_sys_openat fs/open.c:1463 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1463
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0a7ef8f6c9
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:00007f0a7fed8038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f0a7f1e5fa0 RCX: 00007f0a7ef8f6c9
RDX: 000000000000275a RSI: 0000200000000080 RDI: ffffffffffffff9c
RBP: 00007f0a7f011f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0a7f1e6038 R14: 00007f0a7f1e5fa0 R15: 00007ffde7416408
 </TASK>
---[ end trace ]---


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