close leaking slave fd after setting up pty magic

The fd moves out of scope here anyway, so we should close it properly
instead of leaking it which will tickle down to dpkg maintainer scripts.

Closes: 767774

4 files changed, 103 insertions, 60 deletions

diff --git a/apt-pkg/deb/dpkgpm.cc b/apt-pkg/deb/dpkgpm.cc
index 3f6039e0d..dd03eac2c 100644
--- a/apt-pkg/deb/dpkgpm.cc
+++ b/apt-pkg/deb/dpkgpm.cc
@@ -1158,8 +1158,7 @@ void pkgDPkgPM::SetupSlavePtyMagic()
    int const slaveFd = open(d->slave, O_RDWR);
    if (slaveFd == -1)
       _error->FatalE("open", _("Can not write log (%s)"), _("Is /dev/pts mounted?"));
-
-   if (ioctl(slaveFd, TIOCSCTTY, 0) < 0)
+   else if (ioctl(slaveFd, TIOCSCTTY, 0) < 0)
       _error->FatalE("ioctl", "Setting TIOCSCTTY for slave fd %d failed!", slaveFd);
    else
    {
@@ -1170,6 +1169,9 @@ void pkgDPkgPM::SetupSlavePtyMagic()
       if (tcsetattr(0, TCSANOW, &d->tt) < 0)
 	 _error->FatalE("tcsetattr", "Setting in Setup via TCSANOW for slave fd %d failed!", slaveFd);
    }
+
+   if (slaveFd != -1)
+      close(slaveFd);
 }
 void pkgDPkgPM::StopPtyMagic()
 {
diff --git a/test/integration/framework b/test/integration/framework
index 51c7b8cae..ff059f59e 100644
--- a/test/integration/framework
+++ b/test/integration/framework
@@ -358,6 +358,54 @@ configdpkg() {
 	fi
 }
 
+configdpkgnoopchroot() {
+	# create a library to noop chroot() and rewrite maintainer script executions
+	# via execvp() as used by dpkg as we don't want our rootdir to be a fullblown
+	# chroot directory dpkg could chroot into to execute the maintainer scripts
+	msgtest 'Building library to preload to make maintainerscript work in' 'dpkg'
+	cat << EOF > noopchroot.c
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <dlfcn.h>
+
+static char * chrootdir = NULL;
+
+int chroot(const char *path) {
+	printf("WARNING: CHROOTing to %s was ignored!\n", path);
+	free(chrootdir);
+	chrootdir = strdup(path);
+	return 0;
+}
+int execvp(const char *file, char *const argv[]) {
+	static int (*func_execvp) (const char *, char * const []) = NULL;
+	if (func_execvp == NULL)
+		func_execvp = (int (*) (const char *, char * const [])) dlsym(RTLD_NEXT, "execvp");
+	if (chrootdir == NULL || strncmp(file, "/var/lib/dpkg/", strlen("/var/lib/dpkg/")) != 0)
+		return func_execvp(file, argv);
+	printf("REWRITE execvp call %s into %s\n", file, chrootdir);
+	char newfile[strlen(chrootdir) + strlen(file)];
+	strcpy(newfile, chrootdir);
+	strcat(newfile, file);
+	return func_execvp(newfile, argv);
+}
+EOF
+	testsuccess --nomsg gcc -fPIC -shared -o noopchroot.so noopchroot.c -ldl
+
+	mkdir -p "${TMPWORKINGDIRECTORY}/rootdir/usr/bin/"
+	DPKG="${TMPWORKINGDIRECTORY}/rootdir/usr/bin/dpkg"
+	echo "#!/bin/sh
+if [ -n \"\$LD_PRELOAD\" ]; then
+	export LD_PRELOAD=\"${TMPWORKINGDIRECTORY}/noopchroot.so \${LD_PRELOAD}\"
+else
+	export LD_PRELOAD=\"${TMPWORKINGDIRECTORY}/noopchroot.so\"
+fi
+dpkg \"\$@\"" > $DPKG
+	chmod +x $DPKG
+	sed -ie "s|^DPKG::options:: \"dpkg\";\$|DPKG::options:: \"$DPKG\";|" aptconfig.conf
+}
+
 configallowinsecurerepositories() {
     echo "Acquire::AllowInsecureRepositories \"$1\";" >  rootdir/etc/apt/apt.conf.d/allow-insecure-repositories.conf
 
@@ -480,7 +528,7 @@ buildsimplenativepackage() {
 	fi
 	local BUILDDIR=${TMPWORKINGDIRECTORY}/incoming/${NAME}-${VERSION}
 
-	msgninfo "Build package ${NAME} in ${VERSION} for ${RELEASE} in ${DISTSECTION}… "
+	msgtest "Build source package in version ${VERSION} for ${RELEASE} in ${DISTSECTION}" "$NAME"
 	mkdir -p $BUILDDIR/debian/source
 	echo "* most suckless software product ever" > ${BUILDDIR}/FEATURES
 	echo "#!/bin/sh
@@ -512,7 +560,10 @@ Package: $NAME" >> ${BUILDDIR}/debian/control
 	echo "Description: $DESCRIPTION" >> ${BUILDDIR}/debian/control
 
 	echo '3.0 (native)' > ${BUILDDIR}/debian/source/format
-	(cd ${BUILDDIR}/..; dpkg-source -b ${NAME}-${VERSION} 2>&1) | sed -n 's#^dpkg-source: info: building [^ ]\+ in ##p' \
+	cd ${BUILDDIR}/..
+	testsuccess --nomsg dpkg-source -b ${NAME}-${VERSION}
+	cd - >/dev/null
+	sed -n 's#^dpkg-source: info: building [^ ]\+ in ##p' ${TMPWORKINGDIRECTORY}/rootdir/tmp/testsuccess.output \
 		| while read SRC; do
 		echo "pool/${SRC}" >> ${BUILDDIR}/../${RELEASE}.${DISTSECTION}.srclist
 #		if expr match "${SRC}" '.*\.dsc' >/dev/null 2>&1; then
@@ -524,6 +575,7 @@ Package: $NAME" >> ${BUILDDIR}/debian/control
 	done
 
 	for arch in $(getarchitecturesfromcommalist "$ARCH"); do
+		msgtest "Build binary package for ${RELEASE} in ${SECTION}" "$NAME"
 		rm -rf ${BUILDDIR}/debian/tmp
 		mkdir -p ${BUILDDIR}/debian/tmp/DEBIAN ${BUILDDIR}/debian/tmp/usr/share/doc/${NAME} ${BUILDDIR}/debian/tmp/usr/bin
 		cp ${BUILDDIR}/debian/copyright ${BUILDDIR}/debian/changelog ${BUILDDIR}/FEATURES ${BUILDDIR}/debian/tmp/usr/share/doc/${NAME}
@@ -537,11 +589,7 @@ Package: $NAME" >> ${BUILDDIR}/debian/control
 		local LOG="${BUILDDIR}/../${NAME}_${VERSION}_${arch}.dpkg-deb.log"
 		# ensure the right permissions as dpkg-deb ensists
 		chmod 755 ${BUILDDIR}/debian/tmp/DEBIAN
-		if ! dpkg-deb -Z${COMPRESS_TYPE} --build ${BUILDDIR}/debian/tmp ${BUILDDIR}/.. >$LOG 2>&1; then
-			cat $LOG
-			false
-		fi
-		rm $LOG
+		testsuccess --nomsg dpkg-deb -Z${COMPRESS_TYPE} --build ${BUILDDIR}/debian/tmp ${BUILDDIR}/..
 		echo "pool/${NAME}_${VERSION}_${arch}.deb" >> ${BUILDDIR}/../${RELEASE}.${DISTSECTION}.pkglist
 	done
 
@@ -559,15 +607,13 @@ buildpackage() {
 	local ARCH=$(getarchitecture $4)
 	local PKGNAME="$(echo "$BUILDDIR" | grep -o '[^/]*$')"
 	local BUILDLOG="$(readlink -f "${BUILDDIR}/../${PKGNAME}_${RELEASE}_${SECTION}.dpkg-bp.log")"
-	msgninfo "Build package ${PKGNAME} for ${RELEASE} in ${SECTION}… "
+	msgtest "Build package for ${RELEASE} in ${SECTION}" "$PKGNAME"
 	cd $BUILDDIR
 	if [ "$ARCH" = "all" ]; then
 		ARCH="$(dpkg-architecture -qDEB_HOST_ARCH 2> /dev/null)"
 	fi
-	if ! dpkg-buildpackage -uc -us -a$ARCH >$BUILDLOG 2>&1 ; then
-		cat $BUILDLOG
-		false
-	fi
+	testsuccess --nomsg dpkg-buildpackage -uc -us -a$ARCH
+	cp ${TMPWORKINGDIRECTORY}/rootdir/tmp/testsuccess.output $BUILDLOG
 	local PKGS="$(grep '^dpkg-deb: building package' $BUILDLOG | cut -d'/' -f 2 | sed -e "s#'\.##")"
 	local SRCS="$(grep '^dpkg-source: info: building' $BUILDLOG | grep -o '[a-z0-9._+~-]*$')"
 	cd - > /dev/null
@@ -577,7 +623,6 @@ buildpackage() {
 	for SRC in $SRCS; do
 		echo "pool/${SRC}" >> ${TMPWORKINGDIRECTORY}/incoming/${RELEASE}.${SECTION}.srclist
 	done
-	msgdone "info"
 }
 
 buildaptarchive() {
diff --git a/test/integration/test-failing-maintainer-scripts b/test/integration/test-failing-maintainer-scripts
index 3dd7d643e..953506aa5 100755
--- a/test/integration/test-failing-maintainer-scripts
+++ b/test/integration/test-failing-maintainer-scripts
@@ -6,6 +6,7 @@ TESTDIR=$(readlink -f $(dirname $0))
 
 setupenvironment
 configarchitecture 'native'
+configdpkgnoopchroot
 
 # create a bunch of failures
 createfailure() {
@@ -25,51 +26,6 @@ createfailure 'postrm'
 
 setupaptarchive
 
-# create a library to noop chroot() and rewrite maintainer script executions
-# via execvp() as used by dpkg as we don't want our rootdir to be a fullblown
-# chroot directory dpkg could chroot into to execute the maintainer scripts
-cat << EOF > noopchroot.c
-#define _GNU_SOURCE
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <dlfcn.h>
-
-static char * chrootdir = NULL;
-
-int chroot(const char *path) {
-	printf("WARNING: CHROOTing to %s was ignored!\n", path);
-	free(chrootdir);
-	chrootdir = strdup(path);
-	return 0;
-}
-int execvp(const char *file, char *const argv[]) {
-	static int (*func_execvp) (const char *, char * const []) = NULL;
-	if (func_execvp == NULL)
-		func_execvp = (int (*) (const char *, char * const [])) dlsym(RTLD_NEXT, "execvp");
-	if (chrootdir == NULL || strncmp(file, "/var/lib/dpkg/", strlen("/var/lib/dpkg/")) != 0)
-		return func_execvp(file, argv);
-	printf("REWRITE execvp call %s into %s\n", file, chrootdir);
-	char newfile[strlen(chrootdir) + strlen(file)];
-	strcpy(newfile, chrootdir);
-	strcat(newfile, file);
-	return func_execvp(newfile, argv);
-}
-EOF
-testsuccess gcc -fPIC -shared -o noopchroot.so noopchroot.c -ldl
-
-mkdir -p "${TMPWORKINGDIRECTORY}/rootdir/usr/bin/"
-DPKG="${TMPWORKINGDIRECTORY}/rootdir/usr/bin/dpkg"
-echo "#!/bin/sh
-if [ -n \"\$LD_PRELOAD\" ]; then
-	export LD_PRELOAD=\"${TMPWORKINGDIRECTORY}/noopchroot.so \${LD_PRELOAD}\"
-else
-	export LD_PRELOAD=\"${TMPWORKINGDIRECTORY}/noopchroot.so\"
-fi
-dpkg \"\$@\"" > $DPKG
-chmod +x $DPKG
-sed -ie "s|^DPKG::options:: \"dpkg\";\$|DPKG::options:: \"$DPKG\";|" aptconfig.conf
-
 # setup some pre- and post- invokes to check the output isn't garbled later
 APTHOOK="${TMPWORKINGDIRECTORY}/rootdir/usr/bin/apthook"
 echo '#!/bin/sh
diff --git a/test/integration/test-no-fds-leaked-to-maintainer-scripts b/test/integration/test-no-fds-leaked-to-maintainer-scripts
new file mode 100755
index 000000000..6ed120090
--- /dev/null
+++ b/test/integration/test-no-fds-leaked-to-maintainer-scripts
@@ -0,0 +1,40 @@
+#!/bin/sh
+set -e
+
+TESTDIR=$(readlink -f $(dirname $0))
+. $TESTDIR/framework
+
+setupenvironment
+configarchitecture 'native'
+configdpkgnoopchroot
+
+setupsimplenativepackage "fdleaks" 'native' '1.0' 'unstable'
+BUILDDIR="incoming/fdleaks-1.0"
+for script in 'preinst' 'postinst' 'prerm' 'postrm'; do
+	echo '#!/bin/sh
+ls -l /proc/self/fd/' > ${BUILDDIR}/debian/$script
+done
+buildpackage "$BUILDDIR" 'unstable' 'main' 'native'
+rm -rf "$BUILDDIR"
+
+setupaptarchive
+
+testsuccess aptget install -y fdleaks
+msgtest 'Check if fds were not' 'leaked'
+if [ "$(grep 'root root' rootdir/tmp/testsuccess.output | wc -l)" = '8' ]; then
+	msgpass
+else
+	echo
+	cat rootdir/tmp/testsuccess.output
+	msgfail
+fi
+
+testsuccess aptget purge -y fdleaks
+msgtest 'Check if fds were not' 'leaked'
+if [ "$(grep 'root root' rootdir/tmp/testsuccess.output | wc -l)" = '12' ]; then
+	msgpass
+else
+	echo
+	cat rootdir/tmp/testsuccess.output
+	msgfail
+fi