------------[ 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: 7361 Comm: syz.5.162 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+0xe8/0x150
 ubsan_epilogue+0xa/0x40
 __ubsan_handle_out_of_bounds+0xe9/0xf0
 dtInsertEntry+0x936/0x1430
 dtSplitPage+0x2a83/0x3b20
 dtInsert+0x109b/0x5f40
 jfs_mknod+0x640/0x960
 vfs_mknod+0x52b/0x580
 do_mknodat+0x3cc/0x610
 __x64_sys_mknod+0x8c/0xa0
 do_syscall_64+0xec/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1a39d8f7c9
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:00007f1a3acc0038 EFLAGS: 00000246 ORIG_RAX: 0000000000000085
RAX: ffffffffffffffda RBX: 00007f1a39fe5fa0 RCX: 00007f1a39d8f7c9
RDX: 000000000000070b RSI: 0000000000002000 RDI: 0000200000000000
RBP: 00007f1a39df297f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1a39fe6038 R14: 00007f1a39fe5fa0 R15: 00007ffe867c6d08
 </TASK>
---[ end trace ]---
