Beware Old Androids, Active Exploit On Bifrost and Valhall GPU Kernel Drivers

It’s Not Just Old Devices, It’s The Whole Android Patching Process

There was a a use-after-free vulnerability in version r41p0 of the Bifrost and Valhall GPU kernel driver, which was patched back in 2022.  The problem is that when Arm releases a patch, we depend on the device manufacturers to adopt the patch and make it available to their customers.  Once they do, we are often dependant on the phone carriers to then get the patch, possibly conduct internal testing, and finally push it to devices connected to their network.  This is assuming that the carrier doesn’t decide to just pull support for the device completely and offer a new model instead.

All of that complexity makes it quite possible that a two year old vulnerability which should have been patched, is instead a serious concern for users of smartphones, TVs, tablets and even Chromebooks.  In most cases it is not easy to determine what Bifrost or Vallhall driver version is installed on your device; in some cases it is impossible.  If you’ve an Android device that hasn’t seen an update in at least two years you should seriously consider dumping it, if you have a more modern device you might still want to check this site to see if you might be vulnerable.

Sadly there isn’t much you can do other than that, unless someone knows of an app that will give you a full list of the drivers present on your Android devices.