------------[ 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: 20934 Comm: syz.2.1664 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250
 ubsan_epilogue+0xa/0x40
 __ubsan_handle_out_of_bounds+0xe9/0xf0
 dtInsertEntry+0x936/0x1430
 dtSplitPage+0x2a83/0x3b20
 dtInsert+0x109b/0x5f40
 jfs_create+0x6c8/0xa80
 path_openat+0x14f4/0x3830
 do_filp_open+0x1fa/0x410
 do_sys_openat2+0x121/0x1c0
 __x64_sys_creat+0x8f/0xc0
 do_syscall_64+0xfa/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f183bd8f6c9
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:00007f183cc17038 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 00007f183bfe6090 RCX: 00007f183bd8f6c9
RDX: 0000000000000000 RSI: 00000000000000c7 RDI: 0000200000002180
RBP: 00007f183be11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f183bfe6128 R14: 00007f183bfe6090 R15: 00007ffd828da698
 </TASK>
---[ end trace ]---
