mxml-V4.0.2 stack-overflow in Function mxmlLoadString

[ypcd]

mxml-V4.0.2 stack-overflow in Function mxmlLoadString

mxml version: V4.0.2, master(2024-4-13)

clang version: V17.0.6

Computer model: apple macbook air M1 (arm64)

Operating system version: centos steam 9 (kernel 5.14.0-435.el9.aarch64)

I'm building mxml 4.0.2 using clang 17 and AddressSanitizer.
Performing the following operations results in a "stack-overflow" error in the mxmlLoadString function in the "mxml-file.c" file.

error message:

AddressSanitizer:DEADLYSIGNAL
================================================== ===============
==25150==ERROR: AddressSanitizer: stack-overflow on address 0xffffe4b7d1e5 (pc 0xffffe4b7d1e5 bp 0xffffe4b7c000 sp 0xffffe4b7bee0 T0)
/usr/bin/llvm-symbolizer: error: '[stack]': No such file or directory
     #0 0xffffe4b7d1e5 ([stack]+0x201e5)
     #1 0xffffb3c2aeec in mxmlLoadString /home/user2/mxml-master/mxml-file.c:242:11
     #2 0x50cf88 in main /home/user2/mxml-master/./mxml--V4_test_input--.cpp:19:8
     #3 0xffffb36692fc in __libc_start_call_main (/lib64/libc.so.6+0x272fc) (BuildId: ac204fa2b2a4b439262841496e92461f72f00fcb)
     #4 0xffffb36693d4 in __libc_start_main@GLIBC_2.17 (/lib64/libc.so.6+0x273d4) (BuildId: ac204fa2b2a4b439262841496e92461f72f00fcb)
     #5 0x4304ac in _start (/home/user2/mxml-master/mxml_input+0x4304ac) (BuildId: 908a0efe4e2999feab4c16425ebf978ed47bf77f)

SUMMARY: AddressSanitizer: stack-overflow ([stack]+0x201e5)
==25150==ABORTING

Reproduction steps:
mxml--V4.0.2--stack-overflow.zip

Install clang 17.
Unzip the "mxml-4.0.2.tar.gz" file and obtain the "mxml-4.0.2" folder.


The files in the mxml--V4.0.2--stack-overflow.zip compressed package are "mxml--V4_test_input--.cpp", "mxml-V4.0.2--crash--stack-overflow.txt", "run .mxml-V4.input--single-file--.sh", copy to the "mxml-4.0.2" folder.

Under the "mxml-4.0.2" folder, execute the following command:

source run.mxml-V4.input--single-file--.sh or ./run.mxml-V4.input--single-file--.sh
(Be careful not to use sh run.mxml-V4.input--single-file--.sh, the script file will set environment variables)

./mxml_input < ./mxml-V4.0.2--crash--stack-overflow.txt
(Note: The error will not be triggered every time. You will need to run it a few times.)

[michaelrsweet]

OK, so your test code passes an uninitialized mxml_options_t pointer. I'm not able to reproduce when it is initialized to NULL.

I will also advise you not to include the Mini-XML private header since that isn't something you normally will have access to since it is private to the library, subject to change at any time, and not public API...

[ypcd]

Hello, thank you for your reply.
The source code for the example I wrote is wrong.
My example cannot prove that mxml has security vulnerabilities.