------------[ cut here ]------------
UBSAN: array-index-out-of-bounds in fs/jfs/jfs_dtree.c:1601:21
index 26 is out of range for type 'lv [20]'
CPU: 1 UID: 0 PID: 21792 Comm: syz.7.4034 Not tainted syzkaller #0 PREEMPT(full) 
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_symlink+0xc33/0x10f0 fs/jfs/namei.c:1021
 vfs_symlink fs/namei.c:5643 [inline]
 vfs_symlink+0x178/0x4d0 fs/namei.c:5622
 filename_symlinkat+0x2a6/0x560 fs/namei.c:5668
 __do_sys_symlink fs/namei.c:5695 [inline]
 __se_sys_symlink fs/namei.c:5691 [inline]
 __x64_sys_symlink+0x79/0xb0 fs/namei.c:5691
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff7ae39c819
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:00007ff7af2d2028 EFLAGS: 00000246 ORIG_RAX: 0000000000000058
RAX: ffffffffffffffda RBX: 00007ff7ae616270 RCX: 00007ff7ae39c819
RDX: 0000000000000000 RSI: 0000200000001180 RDI: 0000200000000280
RBP: 00007ff7ae432c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff7ae616308 R14: 00007ff7ae616270 R15: 00007ffd3b74bdd8
 </TASK>
---[ end trace ]---