commit dbba87d531ad3ea372eba6cb56436a231ca7fb32
Author: Dmitry V. Levin <ldv@altlinux.org>
Date:   Wed Dec 27 22:12:51 2017 +0000

    elf: check for rpath emptiness before making a copy of it

    * elf/dl-load.c (decompose_rpath): Check for rpath emptiness before
    making a copy of it.

Index: glibc-2.17-c758a686/elf/dl-load.c
===================================================================
--- glibc-2.17-c758a686.orig/elf/dl-load.c
+++ glibc-2.17-c758a686/elf/dl-load.c
@@ -550,7 +550,6 @@ decompose_rpath (struct r_search_path_st
 {
   /* Make a copy we can work with.  */
   const char *where = l->l_name;
-  char *copy;
   char *cp;
   struct r_search_path_elem **result;
   size_t nelems;
@@ -589,22 +588,21 @@ decompose_rpath (struct r_search_path_st
       while (*inhp != '\0');
     }
 
+  /* Ignore empty rpaths.  */
+  if (*rpath == '\0')
+    {
+      sps->dirs = (struct r_search_path_elem **) -1;
+      return false;
+    }
+
   /* Make a writable copy.  */
-  copy = local_strdup (rpath);
+  char *copy = local_strdup (rpath);
   if (copy == NULL)
     {
       errstring = N_("cannot create RUNPATH/RPATH copy");
       goto signal_error;
     }
 
-  /* Ignore empty rpaths.  */
-  if (*copy == 0)
-    {
-      free (copy);
-      sps->dirs = (struct r_search_path_elem **) -1;
-      return false;
-    }
-
   /* Count the number of necessary elements in the result array.  */
   nelems = 0;
   for (cp = copy; *cp != '\0'; ++cp)