KVM: x86: Sysexit emulation does not mask RIP/RSP

commit bf0b682c9b6a6d6d54adf439bfe953feef7be2e8 upstream.

If the operand size is not 64-bit, then the sysexit instruction should assign
ECX to RSP and EDX to RIP.  The current code assigns the full 64-bits.

Fix it by masking.

Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index d28104924255df7686ee4bf968f97fd61e5eea1c..8ab43ac68f0674a98bd48bd4aeed6977ca3233e4 100644 (file)
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -2372,6 +2372,8 @@ static int em_sysexit(struct x86_emulate_ctxt *ctxt)
                if ((msr_data & 0xfffc) == 0x0)
                        return emulate_gp(ctxt, 0);
                ss_sel = (u16)(msr_data + 24);
+               rcx = (u32)rcx;
+               rdx = (u32)rdx;
                break;
        case X86EMUL_MODE_PROT64:
                cs_sel = (u16)(msr_data + 32);