Add a setup hook for detecting $TMPDIR references in RPATHs and wrapper scripts

2017-05-04 20:23:57 +02:00
parent 3b8f8951db
commit 94d164dd7f
3 changed files with 54 additions and 0 deletions
@@ -0,0 +1,41 @@
+# Check whether RPATHs or wrapper scripts contain references to
+# $TMPDIR. This is a serious security bug because it allows any user
+# to inject files into search paths of other users' processes.
+#
+# It might be better to have Nix scan build output for any occurrence
+# of $TMPDIR (which would also be good for reproducibility), but at
+# the moment that would produce too many spurious errors (e.g. debug
+# info or assertion messages that refer to $TMPDIR).
+
+fixupOutputHooks+=('if [ -z "$noAuditTmpdir" -a -e "$prefix" ]; then auditTmpdir "$prefix"; fi')
+
+auditTmpdir() {
+    local dir="$1"
+    [ -e "$dir" ] || return 0
+
+    header "checking for references to $TMPDIR in $dir..."
+
+    local i
+    while IFS= read -r -d $'\0' i; do
+        if [[ "$i" =~ .build-id ]]; then continue; fi
+
+        if isELF "$i"; then
+            if patchelf --print-rpath "$i" | grep -q -F "$TMPDIR"; then
+                echo "RPATH of binary $i contains a forbidden reference to $TMPDIR"
+                exit 1
+            fi
+        fi
+
+        if  isScript "$i"; then
+            if [ -e "$(dirname $i)/.$(basename $i)-wrapped" ]; then
+                if grep -q -F "$TMPDIR" "$i"; then
+                    echo "wrapper script $i contains a forbidden reference to $TMPDIR"
+                    exit 1
+                fi
+            fi
+        fi
+
+    done < <(find "$dir" -type f -print0)
+
+    stopNest
+}