syzbot

loop0: detected capacity change from 0 to 32768
UFO tlock:0xffffc900035212d0
------------[ cut here ]------------
UBSAN: array-index-out-of-bounds in fs/jfs/jfs_dtree.c:3700:8
index -1 is out of range for type 'struct dtslot[128]'
CPU: 0 UID: 0 PID: 6101 Comm: syz.0.28 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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
 dtInsertEntry+0x936/0x1430 fs/jfs/jfs_dtree.c:3700
 dtInsert+0x931/0x5f40 fs/jfs/jfs_dtree.c:894
 jfs_create+0x6c8/0xa80 fs/jfs/namei.c:137
 lookup_open fs/namei.c:4440 [inline]
 open_last_lookups fs/namei.c:4540 [inline]
 path_openat+0x18d1/0x3df0 fs/namei.c:4784
 do_filp_open+0x1fa/0x410 fs/namei.c:4814
 do_sys_openat2+0x121/0x200 fs/open.c:1430
 do_sys_open fs/open.c:1436 [inline]
 __do_sys_creat fs/open.c:1514 [inline]
 __se_sys_creat fs/open.c:1508 [inline]
 __x64_sys_creat+0x8f/0xc0 fs/open.c:1508
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd3a4bff749
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:00007ffcf2bca1c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 00007fd3a4e55fa0 RCX: 00007fd3a4bff749
RDX: 0000000000000000 RSI: 0000000000000040 RDI: 0000200000000580
RBP: 00007fd3a4c83f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd3a4e55fa0 R14: 00007fd3a4e55fa0 R15: 0000000000000002
 </TASK>
---[ end trace ]---