------------[ cut here ]------------
UBSAN: array-index-out-of-bounds in fs/jfs/jfs_dtree.c:1598:11
index 27 is out of range for type 'struct lv[20]'
CPU: 0 UID: 0 PID: 5330 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 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 ubsan_epilogue+0xa/0x30 lib/ubsan.c:233
 __ubsan_handle_out_of_bounds+0xe8/0xf0 lib/ubsan.c:455
 dtSplitPage+0x34bc/0x36a0 fs/jfs/jfs_dtree.c:1598
 dtSplitUp fs/jfs/jfs_dtree.c:1089 [inline]
 dtInsert+0x1080/0x5cb0 fs/jfs/jfs_dtree.c:868
 jfs_symlink+0x8a1/0xfb0 fs/jfs/namei.c:1021
 vfs_symlink+0x18b/0x330 fs/namei.c:5794
 filename_symlinkat+0x1cd/0x410 fs/namei.c:5819
 __do_sys_symlink fs/namei.c:5846 [inline]
 __se_sys_symlink+0x4d/0x2b0 fs/namei.c:5842
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0fc399e159
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:00007f0fc48a6fe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000058
RAX: ffffffffffffffda RBX: 00007f0fc3c26270 RCX: 00007f0fc399e159
RDX: 0000000000000000 RSI: 0000200000001180 RDI: 0000200000000280
RBP: 00007f0fc3a35024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0fc3c26308 R14: 00007f0fc3c26270 R15: 00007ffec177d508
 </TASK>
---[ end trace ]---