CVE-2021-29256: Arm Mali GPU Kernel Driver Use-After-Free Vulnerability

Vulnerability summary

CVE-2021-29256 is a high (CVSS 9.0) Use After Free vulnerability in Arm Mali Graphics Processing Unit (GPU). It is known to be exploited: CISA lists it, first on 07-07-2023. EPSS estimates a 2.99% chance of exploitation in the next 30 days, higher than 87.1% of scored vulnerabilities.

Timeline

1. 24-05-2021
   PublishedVulnerability first disclosed.
2. 07-07-2023
   Added to CISA KEVArm Mali GPU Kernel Driver Use-After-Free Vulnerability
3. 28-07-2023
   CISA remediation dueApply updates per vendor instructions or discontinue use of the product if updates are unavailable.
4. 21-10-2025
   Last modifiedVulnerability information updated.

Description

. The Arm Mali GPU kernel driver allows an unprivileged user to achieve access to freed memory, leading to information disclosure or root privilege escalation. This affects Bifrost r16p0 through r29p0 before r30p0, Valhall r19p0 through r29p0 before r30p0, and Midgard r28p0 through r30p0.

• CWE-416Use After FreeThe product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.