[patch] patch that protects against attackers using /tmp/ns.$user.$display for mischief

wmii-3.1-perm.patch (text/plain), 1.30 KB, created by Armando Di Cianno on 2006-06-22 18:51:31 UTC

diff -uNr wmii-3.1/cmd/wm/wmii wmii-3.1-wmii-perm-patch/cmd/wm/wmii
--- wmii-3.1/cmd/wm/wmii	2006-06-17 07:44:30.000000000 -0400
+++ wmii-3.1-wmii-perm-patch/cmd/wm/wmii	2006-06-22 21:22:38.000000000 -0400
@@ -1,13 +1,33 @@
 #!/bin/sh
 # start wmiiwm and wait for its termination
 
+startup_error() {
+  echo "There was an error starting wmii."
+  [ ! -z "$1" ] && echo "$1"
+  exit 1
+}
+
 wmiiwm -c || exit 1
 
 OLD_PATH=$PATH export OLD_PATH
 PATH=$HOME/.wmii-3:CONFPREFIX/wmii-3:$PATH export PATH
 WMII_ADDRESS=unix!/tmp/ns.$USER.${DISPLAY%.0}/wmii export WMII_ADDRESS
 
-mkdir -m 700 /tmp/ns.$USER.${DISPLAY%.0} 2>/dev/null
+# check to see if the directory exists, and if so, that its permissions are okay
+WMII_TMP_DIR="/tmp/ns.$USER.${DISPLAY%.0}"
+if [ -a ${WMII_TMP_DIR} ]; then
+  if [ -O ${WMII_TMP_DIR} ] && [ -G ${WMII_TMP_DIR} ]; then
+    perms=$(ls -ld ${WMII_TMP_DIR} | sed -e 's/\s.*$//')
+    if [ "$perms" != "drwx------" ]; then
+      startup_error "The wmii tmp directory ${WMII_TMP_DIR} exists, but its permissions are not the correct mode."
+    fi
+  else
+    startup_error "The wmii tmp directory ${WMII_TMP_DIR} exists, but it is not owned by you."
+  fi
+else
+  mkdir -m 700 ${WMII_TMP_DIR} 2>/dev/null
+fi
+
 wmiiwm -a $WMII_ADDRESS &
 wmiiwmpid=$!
 mkdir $HOME/.wmii-3 2>/dev/null && welcome &