Intel MPX Support Is Dead With Linux 5.6

Following on from last week's story that it was looking like Linux 5.6 would drop Intel MPX support, that has now taken place.

Memory Protection Extensions (MPX) is now dead on Linux. It was already effectively dead if using GCC 9.1 and later since the compiler-side support was removed last year while now the kernel support is eliminated in Linux 5.6.

Memory Protection Extensions was designed by Intel for checking of pointer references at run-time to avoid buffer overflows and other potential related vulnerabilities with Skylake and newer processors. But Intel hasn't been maintaining the MPX software support and they have indicated the MPX capabilities is likely to be removed in future Intel CPUs. MPX never really took off with compiler-based sanitizers addressing the same areas more elegantly and not requiring specialized hardware support.

MPX is removed and the kernel nearly 1,700 lines lighter. Intel MPX support had been mainlined in the Linux kernel and GNU Compiler Collection since 2015.