From 546139d41fb1ba0e0f74dbaf85e97a0b92e3f435 Mon Sep 17 00:00:00 2001
From: Mike Frysinger <vapier@gentoo.org>
Date: Mon, 24 Sep 2007 07:09:41 +0000
Subject: [PATCH] fix possible information leak vulnerability when doing a
 merge of configuration files and be better about handling of whitespace in
 $TMP in a few places

svn path=/main/trunk/; revision=7799
---
 bin/etc-update | 33 ++++++++++++++++++++++-----------
 1 file changed, 22 insertions(+), 11 deletions(-)

diff --git a/bin/etc-update b/bin/etc-update
index 0a6a79e9c..268185676 100755
--- a/bin/etc-update
+++ b/bin/etc-update
@@ -367,18 +367,26 @@ Please select from the menu above (-1 to ignore this update): "
 }
 
 function do_merge() {
+	# make sure we keep the merged file in the secure tempdir
+	# so we dont leak any information contained in said file
+	# (think of case where the file has 0600 perms; during the
+	# merging process, the temp file gets umask perms!)
 
 	local file="${1}"
 	local ofile="${2}"
-	local mfile="${2}.merged"
+	local mfile="${TMP}/${2}.merged"
 	local -i my_input=0
 	echo "${file} ${ofile} ${mfile}"
 
-	if [ -e ${mfile} ] ; then
+	if [[ -e ${mfile} ]] ; then
 		echo "A previous version of the merged file exists, cleaning..."
-		rm ${rm_opts} ${mfile}
+		rm ${rm_opts} "${mfile}"
 	fi
 
+	# since mfile will be like $TMP/path/to/original-file.merged, we
+	# need to make sure the full /path/to/ exists ahead of time
+	mkdir -p "${mfile%/*}"
+
 	until (( ${my_input} == -1 )); do
 		echo "Merging ${file} and ${ofile}"
 		$(echo "${merge_command}" |
@@ -402,8 +410,8 @@ Please select from the menu above (-1 to exit, losing this merge): "
 				       chown "$(stat -f %Su:%Sg "${ofile}")" "${mfile}"
 				       chmod $(stat -f %Mp%Lp "${ofile}") "${mfile}"
 				   fi
-				   mv ${mv_opts} ${mfile} ${ofile}
-				   rm ${rm_opts} ${file}
+				   mv ${mv_opts} "${mfile}" "${ofile}"
+				   rm ${rm_opts} "${file}"
 				   return 255
 				   ;;
 				2) ( echo "Showing differences between ${ofile} and ${mfile}"
@@ -417,7 +425,7 @@ Please select from the menu above (-1 to exit, losing this merge): "
 				4) ${EDITOR:-nano -w} "${mfile}"
 				   continue
 					 ;;
-				5) rm ${rm_opts} ${mfile}
+				5) rm ${rm_opts} "${mfile}"
 				   return 0
 				   ;;
 				*) continue
@@ -425,7 +433,7 @@ Please select from the menu above (-1 to exit, losing this merge): "
 			esac
 		done
 	done
-	rm ${rm_opts} ${mfile}
+	rm ${rm_opts} "${mfile}"
 	return 255
 }
 
@@ -439,7 +447,7 @@ function die() {
 		[ ${count} -gt 0 ] && echo "NOTE: ${count} updates remaining"
 	fi
 
-	rm -rf ${TMP}
+	rm -rf "${TMP}"
 	exit ${2}
 }
 
@@ -461,9 +469,12 @@ export PORTAGE_TMPDIR
 #echo $CONFIG_PROTECT_MASK
 #export PORTAGE_TMPDIR=$(/usr/lib/portage/bin/portageq envvar PORTAGE_TMPDIR)
 
-TMP="${PORTAGE_TMPDIR}/$$"
-rm -rf ${TMP} 2> /dev/null
-mkdir ${TMP} || die "failed mkdir command!" 1
+TMP="${PORTAGE_TMPDIR}/etc-update-$$"
+rm -rf "${TMP}" 2> /dev/null
+mkdir "${TMP}" || die "failed to create temp dir" 1
+# make sure we have a secure directory to work in
+chmod 0700 "${TMP}" || die "failed to set perms on temp dir" 1
+chown ${UID:-0}:${GID:-0} "${TMP}" || die "failed to set ownership on temp dir" 1
 
 # I need the CONFIG_PROTECT value
 #CONFIG_PROTECT=$(/usr/lib/portage/bin/portageq envvar CONFIG_PROTECT)
-- 
2.26.2