A security researcher has published technical details on an Arm Mali GPU vulnerability leading to arbitrary kernel code execution and root on Pixel 6 phones using a malicious app installed on the targeted device.
Tracked as CVE-2022-38181 (CVSS score of 8.8), the issue is described as a use-after-free bug that impacts Arm Mali GPU driver versions prior to r40p0 (released on October 7, 2022).
The issue, GitHub Security Lab researcher Man Yue Mo explains, is related to a special function for sending ‘job chains’ to the GPU, but which also supports jobs implemented in the kernel, which run on the CPU instead (and which are called software jobs or softjobs).
“Due to the complexity involved in managing memory sharing between user space applications and the GPU, many of the vulnerabilities in the Arm Mali GPU involve the memory management code. The current vulnerability is another example of this and involves a special type of GPU memory: the JIT memory,” Man Yue Mo notes in a detailed technical description of the vulnerability.
After Arm’s patch in October 2022, Google included a fix for this vulnerability in the January 2023 security update for Pixel devices, but without mentioning the CVE ID or the original bug IDs, the researcher says.