From patchwork Thu May 18 17:37:30 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?b?UmFkaW0gS3LEjW3DocWZ?= X-Patchwork-Id: 9735011 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 9D869601A1 for ; Thu, 18 May 2017 17:40:19 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8A009288D8 for ; Thu, 18 May 2017 17:40:19 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7E557288DA; Thu, 18 May 2017 17:40:19 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,HK_RANDOM_FROM, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4AB8F288D8 for ; Thu, 18 May 2017 17:40:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932963AbdERRjn (ORCPT ); Thu, 18 May 2017 13:39:43 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54914 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932442AbdERRjZ (ORCPT ); Thu, 18 May 2017 13:39:25 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id ADB8B80C1E; Thu, 18 May 2017 17:39:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com ADB8B80C1E Authentication-Results: ext-mx02.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx02.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=rkrcmar@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com ADB8B80C1E Received: from potion (dhcp-1-124.brq.redhat.com [10.34.1.124]) by smtp.corp.redhat.com (Postfix) with SMTP id D7D205DD72; Thu, 18 May 2017 17:39:17 +0000 (UTC) Received: by potion (sSMTP sendmail emulation); Thu, 18 May 2017 19:39:17 +0200 From: =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: Paolo Bonzini , Dan Carpenter Subject: [PATCH 2/4] KVM: x86: zero base3 of unusable segments Date: Thu, 18 May 2017 19:37:30 +0200 Message-Id: <20170518173732.12185-3-rkrcmar@redhat.com> In-Reply-To: <20170518173732.12185-1-rkrcmar@redhat.com> References: <20170518173732.12185-1-rkrcmar@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Thu, 18 May 2017 17:39:19 +0000 (UTC) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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") Signed-off-by: Radim Krčmář Reviewed-by: David Hildenbrand --- 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 b54125b590e8..eed8272dd52e 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5053,6 +5053,8 @@ 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; }