Commit 8b9f4414 authored by Gleb Natapov's avatar Gleb Natapov Committed by Marcelo Tosatti
Browse files

KVM: x86 emulator: Forbid modifying CS segment register by mov instruction 



Inject #UD if guest attempts to do so. This is in accordance to Intel
SDM.

Cc: stable@kernel.org (2.6.33, 2.6.32)
Signed-off-by: default avatarGleb Natapov <gleb@redhat.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent 70e335e1

arch/x86/kvm/emulate.c

+6 −0
Original line number Diff line number Diff line
@@ -2126,6 +2126,12 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) 
		int err;



		sel = c->src.val;



		if (c->modrm_reg == VCPU_SREG_CS) {

			kvm_queue_exception(ctxt->vcpu, UD_VECTOR);

			goto done;

		}



		if (c->modrm_reg == VCPU_SREG_SS)

			toggle_interruptibility(ctxt, X86_SHADOW_INT_MOV_SS);