SB20260727341 - Improper Check or Handling of Exceptional Conditions in Linux kernel kernel cpu

Description

This security bulletin contains information about 1 vulnerability.

1) Improper Check or Handling of Exceptional Conditions (CVE-ID: CVE-2026-64229)

CWE-ID: CWE-703 - Improper Check or Handling of Exceptional Conditions

CVSSv4: 6.8 [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]

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

The vulnerability exists due to improper hardware feature dependency handling in broadcast TLB flush logic when performing TLB invalidation with a non-zero PCID while PCID is disabled via the "nopcid" boot option. A local user can trigger memory-management operations that reach the broadcast TLB flush path to cause a denial of service.

The issue occurs only in the "nopcid" scenario on AMD CPUs that support INVLPGB, and can result in a general protection fault in the kernel.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/44126343d58c68adaa8343fbf1c07dd20078c35e
• https://git.kernel.org/stable/c/d2d6d21286719b454d5d87a8758c23d2377d88a2
• https://git.kernel.org/stable/c/fed725cace3ab1c4f7f8182e35029a603d953187