CVE-2022-49078

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/[email protected]/ [2] https://github.com/lz4/lz4/commit/c5d6f8a8be3927c0bec91bcc58667a6cfad244ad# [3] https://lore.kernel.org/all/[email protected]/

This vulnerability is rated as Moderate because exploitation requires local access and the ability to feed specially crafted, corrupted compressed data to in-kernel LZ4 decompression routines. A successful exploit could trigger an out-of-bounds read or use-after-free condition, resulting in a system crash and denial of service or potentially minor information disclosure. Because exploitation is confined to local environments and does not directly permit arbitrary code execution or privilege escalation across boundaries, the overall risk to Red Hat Enterprise Linux systems remains contained.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.