From 378a8b099fc207ddcb91b19a8c1457667e0af398 Mon Sep 17 00:00:00 2001 From: Gleb Natapov Date: Mon, 21 Jan 2013 15:36:48 +0200 Subject: [PATCH] KVM: x86: fix use of uninitialized memory as segment descriptor in emulator. If VMX reports segment as unusable, zero descriptor passed by the emulator before returning. Such descriptor will be considered not present by the emulator. Signed-off-by: Gleb Natapov Signed-off-by: Marcelo Tosatti --- arch/x86/kvm/x86.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index e00dd0515a84..b9f55299ed7e 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -4489,8 +4489,10 @@ static bool emulator_get_segment(struct x86_emulate_ctxt *ctxt, u16 *selector, kvm_get_segment(emul_to_vcpu(ctxt), &var, seg); *selector = var.selector; - if (var.unusable) + if (var.unusable) { + memset(desc, 0, sizeof(*desc)); return false; + } if (var.g) var.limit >>= 12; -- 2.30.2