CVE-2022-49557 x86/fpu: KVM: Set the base guest FPU uABI size to sizeof(struct kvm_xsave)

In the Linux kernel, the following vulnerability has been resolved: x86/fpu: KVM: Set the base guest FPU uABI size to sizeofstruct kvmxsave Set the starting uABI size of KVM's guest FPU to 'struct kvmxsave', i.e. to KVM's historical uABI size. When saving FPU state for usersapce, KVM well, now th...

CVE-2022-49557

CVE-2022-49557 affects the Linux kernel in x86/fpu/KVM. The root cause is KVM’s guest FPU uABI size being set to the host default instead of KVM’s historic size, causing out-of-bounds writes to the XSAVE header when saving FPU state for guests on hosts without XSAVE. This can lead to data corrupt...