In this post, I’ll look at CVE-2023-6241, a vulnerability in the Arm Mali GPU that I reported to Arm on November 15, 2023 and was fixed in the Arm Mali driver version r47p0, which was released publicly on December 14, 2023. It was fixed in Android in the March security update. When exploited, this vulnerability allows a malicious Android app to gain arbitrary kernel code execution and root on the device. The vulnerability affects devices with newer Arm Mali GPUs that use the Command Stream Frontend (CSF) feature, such as Google’s Pixel 7 and Pixel 8 phones. What is interesting about this vulnerability is that it is a logic bug in the memory management unit of the Arm Mali GPU and it is capable of bypassing Memory Tagging Extension (MTE), a new and powerful mitigation against memory corruption that was first supported in Pixel 8. In this post, I’ll show how to use this bug to gain arbitrary kernel code execution in the Pixel 8 from an untrusted user application. I have confirmed that the exploit works successfully even with kernel MTE enabled by following these instructions.

source: HN