From patchwork Mon Nov 14 14:44:29 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Avi Kivity X-Patchwork-Id: 125544 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [140.186.70.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id BA3D8B71E8 for ; Tue, 15 Nov 2011 01:44:52 +1100 (EST) Received: from localhost ([::1]:48715 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RPxmC-0008T2-Oz for incoming@patchwork.ozlabs.org; Mon, 14 Nov 2011 09:44:48 -0500 Received: from eggs.gnu.org ([140.186.70.92]:36054) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RPxm7-0008SJ-GR for qemu-devel@nongnu.org; Mon, 14 Nov 2011 09:44:44 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1RPxm6-00021C-A8 for qemu-devel@nongnu.org; Mon, 14 Nov 2011 09:44:43 -0500 Received: from mx1.redhat.com ([209.132.183.28]:62841) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RPxm6-000216-3B for qemu-devel@nongnu.org; Mon, 14 Nov 2011 09:44:42 -0500 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id pAEEid1o007471 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Mon, 14 Nov 2011 09:44:39 -0500 Received: from cleopatra.tlv.redhat.com (cleopatra.tlv.redhat.com [10.35.255.11]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id pAEEicF8004259; Mon, 14 Nov 2011 09:44:39 -0500 Received: from s01.tlv.redhat.com (s01.tlv.redhat.com [10.35.255.8]) by cleopatra.tlv.redhat.com (Postfix) with ESMTP id 995D7250B2E; Mon, 14 Nov 2011 16:44:35 +0200 (IST) From: Avi Kivity To: Anthony Liguori , qemu-devel@nongnu.org, Blue Swirl Date: Mon, 14 Nov 2011 16:44:29 +0200 Message-Id: <1321281869-4280-1-git-send-email-avi@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 3) X-Received-From: 209.132.183.28 Cc: Paul Moore Subject: [Qemu-devel] [PATCH v2 1.0] configure: build position independent executables across the board, by default X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Change the default to building PIE (position independent executables); instead of restricting the option to user-only targets, apply it to all targets. In addition, set the relocation sections to read-only (relro) when available; this reduces the attack surface by disallowing changes to relocation tables at runtime. While PIE reduces performance and relro increases load time, it greatly improves security, with the potential to reduce a code execution vulnerability to a self denial of service. Signed-off-by: Avi Kivity --- v2: improves description to include relro While we are past the feature freeze, I feel this deserves an exception. I'd much rather see "CVE-2012-wxyz QEMU Self denial of service" than "CVE-2012-wxyz QEMU code execution". The fact that the option is available for user targets implies that it is compatible with TCG, and some light testing agrees. configure | 35 +++++++++++++++++------------------ 1 files changed, 17 insertions(+), 18 deletions(-) diff --git a/configure b/configure index 6c77fbb..7436361 100755 --- a/configure +++ b/configure @@ -172,7 +172,7 @@ aix="no" blobs="yes" pkgversion="" check_utests="" -user_pie="no" +pie="yes" zero_malloc="" trace_backend="nop" trace_file="trace" @@ -701,9 +701,9 @@ for opt do ;; --disable-guest-base) guest_base="no" ;; - --enable-user-pie) user_pie="yes" + --enable-pie) pie="yes" ;; - --disable-user-pie) user_pie="no" + --disable-pie) pie="no" ;; --enable-uname-release=*) uname_release="$optarg" ;; @@ -1031,8 +1031,8 @@ echo " --disable-bsd-user disable all BSD usermode emulation targets" echo " --enable-guest-base enable GUEST_BASE support for usermode" echo " emulation targets" echo " --disable-guest-base disable GUEST_BASE support" -echo " --enable-user-pie build usermode emulation targets as PIE" -echo " --disable-user-pie do not build usermode emulation targets as PIE" +echo " --enable-pie build Position Independent Executables" +echo " --disable-pie do not build Position Independent Executables" echo " --fmod-lib path to FMOD library" echo " --fmod-inc path to FMOD includes" echo " --oss-lib path to OSS library" @@ -1099,6 +1099,17 @@ for flag in $gcc_flags; do fi done +if test "$pie" = "yes" ; then + QEMU_CFLAGS="-fPIE -DPIE $QEMU_CFLAGS" + LDFLAGS="-Wl,-pie $LDFLAGS" + cat > $TMPC << EOF +int main(void) { return 0; } +EOF + if compile_prog "-fPIE -DPIE" "-Wl,-pie -Wl,-z,relro -Wl,-z,now"; then + LDFLAGS="-Wl,-z,relro -Wl,-z,now $LDFLAGS" + fi +fi + # # Solaris specific configure tool chain decisions # @@ -2765,7 +2776,7 @@ echo "Documentation $docs" echo "uname -r $uname_release" echo "NPTL support $nptl" echo "GUEST_BASE $guest_base" -echo "PIE user targets $user_pie" +echo "PIE $pie" echo "vde support $vde" echo "Linux AIO support $linux_aio" echo "ATTR/XATTR support $attr" @@ -3225,9 +3236,6 @@ for d in libdis libdis-user; do symlink $source_path/Makefile.dis $d/Makefile echo > $d/config.mak done -if test "$static" = "no" -a "$user_pie" = "yes" ; then - echo "QEMU_CFLAGS+=-fpie" > libdis-user/config.mak -fi for target in $target_list; do target_dir="$target" @@ -3646,12 +3654,6 @@ if test "$target_softmmu" = "yes" ; then esac fi -if test "$target_user_only" = "yes" -a "$static" = "no" -a \ - "$user_pie" = "yes" ; then - cflags="-fpie $cflags" - ldflags="-pie $ldflags" -fi - if test "$target_softmmu" = "yes" -a \( \ "$TARGET_ARCH" = "microblaze" -o \ "$TARGET_ARCH" = "cris" \) ; then @@ -3775,9 +3777,6 @@ d=libuser mkdir -p $d mkdir -p $d/trace symlink $source_path/Makefile.user $d/Makefile -if test "$static" = "no" -a "$user_pie" = "yes" ; then - echo "QEMU_CFLAGS+=-fpie" > $d/config.mak -fi if test "$docs" = "yes" ; then mkdir -p QMP