CVE-2022-49078 Information

Description

In the Linux kernel the following vulnerability has been resolved:

lz4: fix LZ4_decompress_safe_partial read out of bound

When partialDecoding it is EOF if we’ve either filled the output buffer or can’t proceed with reading an offset for following match.

In some extreme corner cases when compressed data is suitably corrupted UAF will occur. As reported by KASAN [1] LZ4_decompress_safe_partial may lead to read out of bound problem during decoding. lz4 upstream has fixed it [2] and this issue has been disscussed here [3] before.

current decompression routine was ported from lz4 v1.8.3 bumping lib/lz4 to v1.9.+ is certainly a huge work to be done later so we’d better fix it first.

[1] https://lore.kernel.org/all/000000000000830d1205cf7f0477@google.com/ [2] https://github.com/lz4/lz4/commit/c5d6f8a8be3927c0bec91bcc58667a6cfad244ad [3] https://lore.kernel.org/all/CC666AE8-4CA4-4951-B6FB-A2EFDE3AC03B@fb.com/

Reference

https://git.kernel.org/stable/c/467d5e200ab4486b744fe1776154a43d1aa22d4b https://git.kernel.org/stable/c/6adc01a7aa37445dafe8846faa0610a86029b253 https://git.kernel.org/stable/c/73953dfa9d50e5c9fe98ee13fd1d3427aa12a0a3 https://git.kernel.org/stable/c/9fb8bc6cfc58773ce95414e11c9ccc8fc6ac4927 https://git.kernel.org/stable/c/e64dbe97c05c769525cbca099ddbd22485630235 https://git.kernel.org/stable/c/eafc0a02391b7b36617b36c97c4b5d6832cf5e24