Posts Tagged ‘QualcommAdreno’
[DefCon32] The Way to Android Root: Exploiting Smartphone GPU
Xiling Gong and Eugene Rodionov, security researchers at Google, delve into the vulnerabilities of Qualcomm’s Adreno GPU, a critical component in Android devices. Their presentation uncovers nine exploitable flaws leading to kernel code execution, demonstrating a novel exploit method that bypasses Android’s CFI and W^X mitigations. Xiling and Eugene’s work highlights the risks in GPU drivers and proposes actionable mitigations to enhance mobile security.
Uncovering Adreno GPU Vulnerabilities
Xiling opens by detailing their analysis of the Adreno GPU kernel module, prevalent in Qualcomm-based devices. Their research identified nine vulnerabilities, including race conditions and integer overflows, exploitable from unprivileged apps. These flaws, discovered through meticulous fuzzing, expose the GPU’s complex attack surface, making it a prime target for local privilege escalation.
Novel Exploit Techniques
Eugene describes their innovative exploit method, leveraging GPU features to achieve arbitrary physical memory read/write. By exploiting a race condition, they achieved kernel code execution with 100% success on a fully patched Android device. This technique bypasses Control-flow Integrity (CFI) and Write XOR Execute (W^X) protections, demonstrating the potency of GPU-based attacks and the need for robust defenses.
Challenges in GPU Security
The duo highlights the difficulties in securing GPU drivers, which are accessible to untrusted code and critical for performance. Xiling notes that Android’s reliance on in-process GPU handling, unlike isolated IPC mechanisms, exacerbates risks. Their fuzzing efforts, tailored for concurrent code, revealed the complexity of reproducing and mitigating these vulnerabilities, underscoring the need for advanced testing.
Proposing Robust Mitigations
Concluding, Eugene suggests moving GPU operations to out-of-process handling and adopting memory-safe languages to reduce vulnerabilities. Their work, published via Google’s Android security research portal, calls for vendor action to limit attack surfaces. By sharing their exploit techniques, Xiling and Eugene inspire the community to strengthen mobile security against evolving threats.