SB20260912173 - Out-of-bounds write in Linux kernel erofs

Description

This security bulletin contains information about 1 vulnerability.

1) Out-of-bounds write (CVE-ID: CVE-2026-89602)

CWE-ID: CWE-787 - Out-of-bounds write

CVSSv4: 1.8 [CVSS:4.0/AV:L/AC:L/AT:P/PR:H/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N]

The vulnerability allows a local privileged user to cause memory corruption.

The vulnerability exists due to an out-of-bounds write in the z_erofs_gbuf_growsize() global-buffer resizing function when retrying a global-buffer resize with an intermediate size after a partial resize. A local privileged user can trigger a resize retry using an intermediate size to cause memory corruption.

The issue requires some global buffers to have been enlarged by a previous resize attempt.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/7267557ce98ccd07faaf3bc86382448950cc4ff6
• https://git.kernel.org/stable/c/7f4a89d4f0d6acaf4b756c31de48f2109a257b70
• https://git.kernel.org/stable/c/a7d097cf01301c5da37927c8f26123d006f0fd8a