Hardening the Kernel in Android Oreo (Android Developers Blog)
The Android Developers Blog has anoverview of the security features added to the kernel in the Android"Oreo" release. "Usercopy functions are used by the kernel totransfer data from user space to kernel space memory and back again. Since2014, missing or invalid bounds checking has caused about 45% of Android'skernel vulnerabilities. Hardened usercopy adds bounds checking to usercopyfunctions, which helps developers spot misuse and fix bugs in theircode. Also, if obscure driver bugs slip through, hardening these functionsprevents the exploitation of such bugs."