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UBSAN: array-index-out-of-bounds in fs/jfs/jfs_dtree.c:1601:11
index 26 is out of range for type 'struct lv[20]'
CPU: 1 PID: 6874 Comm: syz.1.216 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
 ubsan_epilogue+0xa/0x30 lib/ubsan.c:217
 __ubsan_handle_out_of_bounds+0xe3/0xf0 lib/ubsan.c:348
 dtSplitPage+0x38be/0x3b10 fs/jfs/jfs_dtree.c:1601
 dtSplitUp fs/jfs/jfs_dtree.c:1092 [inline]
 dtInsert+0x108f/0x5f40 fs/jfs/jfs_dtree.c:871
 jfs_mkdir+0x6c6/0xa30 fs/jfs/namei.c:270
 vfs_mkdir+0x296/0x440 fs/namei.c:4113
 do_mkdirat+0x1d4/0x440 fs/namei.c:4136
 __do_sys_mkdirat fs/namei.c:4151 [inline]
 __se_sys_mkdirat fs/namei.c:4149 [inline]
 __x64_sys_mkdirat+0x89/0xa0 fs/namei.c:4149
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f571958d717
Code: 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 02 01 00 00 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:00007f571a476e68 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f571a476ef0 RCX: 00007f571958d717
RDX: 00000000000001ff RSI: 0000200000000680 RDI: 00000000ffffff9c
RBP: 0000200000000080 R08: 0000200000000140 R09: 0000000000000000
R10: 0000200000000080 R11: 0000000000000246 R12: 0000200000000680
R13: 00007f571a476eb0 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
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