Check strdup() failure

libselinux/utils/getconlist.c

@@ -27,6 +27,11 @@ int main(int argc, char **argv)
 		switch (opt) {
 		case 'l':
 			level = strdup(optarg);
+			if (!level) {
+				fprintf(stderr, "memory allocation failure: %d(%s)\n",
+					errno, strerror(errno));
+				return 3;
+			}
 			break;
 		default:
 			usage(argv[0], "invalid option", 1);