ASA-2019-00654 – Linux kernel: Memory corruption due to the use of cached fpu_fpregs_owner_ctx

fpregs_state_valid in arch/x86/include/asm/fpu/internal.h in the Linux kernel, when GCC 9 is used, allows context-dependent attackers to cause a denial of service (memory corruption) or possibly have unspecified other impact because of incorrect fpu_fpregs_owner_ctx caching, as demonstrated by mishandling of signal-based non-cooperative preemption in Go 1.14 prereleases on amd64.