From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934638AbdKAVag (ORCPT ); Wed, 1 Nov 2017 17:30:36 -0400 Received: from wtarreau.pck.nerim.net ([62.212.114.60]:35545 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934364AbdKAVae (ORCPT ); Wed, 1 Nov 2017 17:30:34 -0400 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, linux@roeck-us.net Cc: =?utf-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= , Willy Tarreau Subject: [PATCH 3.10 107/139] KVM: x86: zero base3 of unusable segments Date: Wed, 1 Nov 2017 22:26:32 +0100 Message-Id: <1509571624-5001-8-git-send-email-w@1wt.eu> X-Mailer: git-send-email 2.8.0.rc2.1.gbe9624a In-Reply-To: <1509571624-5001-1-git-send-email-w@1wt.eu> References: <1509571159-4405-1-git-send-email-w@1wt.eu> <1509571624-5001-1-git-send-email-w@1wt.eu> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Radim Krčmář commit f0367ee1d64d27fa08be2407df5c125442e885e3 upstream. Static checker noticed that base3 could be used uninitialized if the segment was not present (useable). Random stack values probably would not pass VMCS entry checks. Reported-by: Dan Carpenter Fixes: 1aa366163b8b ("KVM: x86 emulator: consolidate segment accessors") Reviewed-by: Paolo Bonzini Reviewed-by: David Hildenbrand Signed-off-by: Radim Krčmář Signed-off-by: Willy Tarreau --- arch/x86/kvm/x86.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index b70b67b..3d316ca 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -4596,6 +4596,8 @@ static bool emulator_get_segment(struct x86_emulate_ctxt *ctxt, u16 *selector, if (var.unusable) { memset(desc, 0, sizeof(*desc)); + if (base3) + *base3 = 0; return false; } -- 2.8.0.rc2.1.gbe9624a