# CVE-2022-49078: lz4: fix LZ4\_decompress\_safe\_partial read out of bound

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2025-02-26 · Updated: 2026-08-05

## Affected

- Linux: version range not reported
- Linux: 4.20

## 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/

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
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## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

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

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