Driving forward in Android drivers

Google’s own Project Zero security research effort, which often finds and publishes vulnerabilities in both other companies’ and its own products, set its sights on Android once more, this time focusing on third-party kernel drivers.

Android’s open-source ecosystem has led to an incredible diversity of manufacturers and vendors developing software that runs on a broad variety of hardware. This hardware requires supporting drivers, meaning that many different codebases carry the potential to compromise a significant segment of Android phones. There are recent public examples of third-party drivers containing serious vulnerabilities that are exploited on Android. While there exists a well-established body of public (and In-the-Wild) security research on Android GPU drivers, other chipset components may not be as frequently audited so this research sought to explore those drivers in greater detail.

Seth Jenkins

They found a whole host of security issues in these third-party kernel drivers in phones both from Google itself as well as from other companies. An interesting point the authors make is that because it’s getting ever harder to find 0-days in core Android, people with nefarious intent are looking at other parts of an Android system now, and these kernel drivers are an inviting avenue for them. They seem to focus mostly on GPU drivers, for now, but it stands to reason they’ll be targeting other drivers, too.

As usual with Android, the discovered exploits were often fixed, but the patches took way, way too long to find their way to end users due to the OEMs lagging behind when it comes to sending those patches to users. The authors propose wider adoption of Android APEX to make it easier to OEMs to deliver kernel patches to users faster.

I always like the Project Zero studies and articles, because they really take no prisoners, and whether they’re investigating someone else like Microsoft or Apple, or their own company Google, they go in hard, do not surgarcoat their findings, and apply the same standards to everyone.