SB20260406102 - NULL pointer dereference in Linux kernel resctrl driver

Description

This security bulletin contains information about 1 vulnerability.

1) NULL pointer dereference (CVE-ID: CVE-2026-23433)

CWE-ID: CWE-476 - NULL Pointer Dereference

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to a null pointer dereference in mpam_restore_mbwu_state() when restoring bandwidth counters after an MSC supporting memory bandwidth monitoring is brought offline and then online. A local user can trigger the affected restore path to cause a denial of service.

This results in a kernel oops. The issue occurs because a value used by __ris_msmon_read() is not initialized before it is accessed.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/4ad79c874e53ebb7fe3b8ae7ac6c858a2121f415
• https://git.kernel.org/stable/c/ac3e12bc195786d3d44d730b5b2259fd36191848