1 files changed, 39 insertions, 0 deletions
diff --git a/nixpkgs/pkgs/build-support/setup-hooks/audit-tmpdir.sh b/nixpkgs/pkgs/build-support/setup-hooks/audit-tmpdir.sh
new file mode 100644
index 000000000000..36714178156b
--- /dev/null
+++ b/nixpkgs/pkgs/build-support/setup-hooks/audit-tmpdir.sh
@@ -0,0 +1,39 @@
+# 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-}" && -e "$prefix" ]]; then auditTmpdir "$prefix"; fi')
+
+auditTmpdir() {
+    local dir="$1"
+    [ -e "$dir" ] || return 0
+
+    echo "checking for references to $TMPDIR/ in $dir..."
+
+    local i
+    find "$dir" -type f -print0 | while IFS= read -r -d $'\0' i; do
+        if [[ "$i" =~ .build-id ]]; then continue; fi
+
+        if isELF "$i"; then
+            if { printf :; patchelf --print-rpath "$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
+}