------------[ cut here ]------------
UBSAN: array-index-out-of-bounds in fs/jfs/jfs_dtree.c:1601:21
index 27 is out of range for type 'lv [20]'
CPU: 1 UID: 0 PID: 16492 Comm: syz.3.2728 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 ubsan_epilogue+0xa/0x30 lib/ubsan.c:233
 __ubsan_handle_out_of_bounds+0xcc/0xf0 lib/ubsan.c:455
 dtSplitPage+0x2db4/0x3740 fs/jfs/jfs_dtree.c:1601
 dtSplitUp+0x7ec/0x5920 fs/jfs/jfs_dtree.c:1092
 dtInsert+0x8dd/0xb40 fs/jfs/jfs_dtree.c:871
 jfs_mknod+0x562/0x9c0 fs/jfs/namei.c:1413
 vfs_mknod+0x3a5/0x7f0 fs/namei.c:5120
 filename_mknodat+0x5aa/0x7f0 fs/namei.c:5179
 __do_sys_mknod fs/namei.c:5207 [inline]
 __se_sys_mknod fs/namei.c:5204 [inline]
 __x64_sys_mknod+0x8f/0xc0 fs/namei.c:5204
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6f7479c819
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f6f756b9028 EFLAGS: 00000246 ORIG_RAX: 0000000000000085
RAX: ffffffffffffffda RBX: 00007f6f74a16090 RCX: 00007f6f7479c819
RDX: 0000000000000707 RSI: 0000000000001000 RDI: 0000200000000080
RBP: 00007f6f74832c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6f74a16128 R14: 00007f6f74a16090 R15: 00007ffea945ff88
 </TASK>
---[ end trace ]---