From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752022AbdIIWi6 (ORCPT ); Sat, 9 Sep 2017 18:38:58 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:41544 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751895AbdIIWYo (ORCPT ); Sat, 9 Sep 2017 18:24:44 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Marcelo Tosatti" , "Gleb Natapov" Date: Sat, 09 Sep 2017 22:47:39 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 036/106] KVM: x86: fix use of uninitialized memory as segment descriptor in emulator. In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.93-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Gleb Natapov commit 378a8b099fc207ddcb91b19a8c1457667e0af398 upstream. 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 Signed-off-by: Ben Hutchings --- arch/x86/kvm/x86.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -4611,8 +4611,10 @@ static bool emulator_get_segment(struct 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;