From b7d6f75072b3569d7d2acce04669e72086b547cb Mon Sep 17 00:00:00 2001
From: Noah Misch <noah@leadboat.com>
Date: Mon, 6 Nov 2017 07:11:10 -0800
Subject: [PATCH] start-scripts: switch to $PGUSER before opening $PGLOG.

By default, $PGUSER has permission to unlink $PGLOG.  If $PGUSER
replaces $PGLOG with a symbolic link, the server will corrupt the
link-targeted file by appending log messages.  Since these scripts open
$PGLOG as root, the attack works regardless of target file ownership.

"make install" does not install these scripts anywhere.  Users having
manually installed them in the past should repeat that process to
acquire this fix.  Most script users have $PGLOG writable to root only,
located in $PGDATA.  Just before updating one of these scripts, such
users should rename $PGLOG to $PGLOG.old.  The script will then recreate
$PGLOG with proper ownership.

Reviewed by Peter Eisentraut.  Reported by Antoine Scemama.

Security: CVE-2017-12172
---
 contrib/start-scripts/freebsd        | 4 ++--
 contrib/start-scripts/linux          | 4 ++--
 contrib/start-scripts/osx/PostgreSQL | 8 ++++----
 3 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/contrib/start-scripts/freebsd b/contrib/start-scripts/freebsd
index 758574b427..e37421253d 100644
--- a/contrib/start-scripts/freebsd
+++ b/contrib/start-scripts/freebsd
@@ -44,7 +44,7 @@ test -x $DAEMON ||
 
 case $1 in
     start)
-	su -l $PGUSER -c "$DAEMON -D '$PGDATA' &" >>$PGLOG 2>&1
+	su -l $PGUSER -c "$DAEMON -D '$PGDATA' >>$PGLOG 2>&1 &"
 	echo -n ' postgresql'
 	;;
     stop)
@@ -52,7 +52,7 @@ case $1 in
 	;;
     restart)
 	su -l $PGUSER -c "$PGCTL stop -D '$PGDATA' -s -m fast -w"
-	su -l $PGUSER -c "$DAEMON -D '$PGDATA' &" >>$PGLOG 2>&1
+	su -l $PGUSER -c "$DAEMON -D '$PGDATA' >>$PGLOG 2>&1 &"
 	;;
     status)
 	su -l $PGUSER -c "$PGCTL status -D '$PGDATA'"
diff --git a/contrib/start-scripts/linux b/contrib/start-scripts/linux
index 763a8064ab..a37ac8b9ab 100644
--- a/contrib/start-scripts/linux
+++ b/contrib/start-scripts/linux
@@ -92,7 +92,7 @@ case $1 in
   start)
 	echo -n "Starting PostgreSQL: "
 	test -e "$PG_OOM_ADJUST_FILE" && echo "$PG_MASTER_OOM_SCORE_ADJ" > "$PG_OOM_ADJUST_FILE"
-	su - $PGUSER -c "$DAEMON_ENV $DAEMON -D '$PGDATA' &" >>$PGLOG 2>&1
+	su - $PGUSER -c "$DAEMON_ENV $DAEMON -D '$PGDATA' >>$PGLOG 2>&1 &"
 	echo "ok"
 	;;
   stop)
@@ -104,7 +104,7 @@ case $1 in
 	echo -n "Restarting PostgreSQL: "
 	su - $PGUSER -c "$PGCTL stop -D '$PGDATA' -s -m fast -w"
 	test -e "$PG_OOM_ADJUST_FILE" && echo "$PG_MASTER_OOM_SCORE_ADJ" > "$PG_OOM_ADJUST_FILE"
-	su - $PGUSER -c "$DAEMON_ENV $DAEMON -D '$PGDATA' &" >>$PGLOG 2>&1
+	su - $PGUSER -c "$DAEMON_ENV $DAEMON -D '$PGDATA' >>$PGLOG 2>&1 &"
 	echo "ok"
 	;;
   reload)
diff --git a/contrib/start-scripts/osx/PostgreSQL b/contrib/start-scripts/osx/PostgreSQL
index c6a19d2e00..3de9de6416 100755
--- a/contrib/start-scripts/osx/PostgreSQL
+++ b/contrib/start-scripts/osx/PostgreSQL
@@ -81,9 +81,9 @@ StartService () {
     if [ "${POSTGRESQL:=-NO-}" = "-YES-" ]; then
         ConsoleMessage "Starting PostgreSQL database server"
         if [ "${ROTATELOGS}" = "1" ]; then
-            sudo -u $PGUSER sh -c "${DAEMON} -D '${PGDATA}' &" 2>&1 | ${LOGUTIL} "${PGLOG}" ${ROTATESEC} &
+            sudo -u $PGUSER sh -c "${DAEMON} -D '${PGDATA}' 2>&1 | ${LOGUTIL} \"${PGLOG}\" ${ROTATESEC} &"
         else
-            sudo -u $PGUSER sh -c "${DAEMON} -D '${PGDATA}' &" >>"$PGLOG" 2>&1
+            sudo -u $PGUSER sh -c "${DAEMON} -D '${PGDATA}' >>\"$PGLOG\" 2>&1 &"
         fi
     fi
 }
@@ -100,9 +100,9 @@ RestartService () {
 	sudo -u $PGUSER sh -c "$PGCTL stop -D '${PGDATA}' -s -m fast"
 	# should match StartService:
         if [ "${ROTATELOGS}" = "1" ]; then
-            sudo -u $PGUSER sh -c "${DAEMON} -D '${PGDATA}' &" 2>&1 | ${LOGUTIL} "${PGLOG}" ${ROTATESEC} &
+            sudo -u $PGUSER sh -c "${DAEMON} -D '${PGDATA}' 2>&1 | ${LOGUTIL} \"${PGLOG}\" ${ROTATESEC} &"
         else
-            sudo -u $PGUSER sh -c "${DAEMON} -D '${PGDATA}' &" >>"$PGLOG" 2>&1
+            sudo -u $PGUSER sh -c "${DAEMON} -D '${PGDATA}' >>\"$PGLOG\" 2>&1 &"
         fi
     else
         StopService
-- 
2.40.0