eglibc: add security patch for CVE-2013-4788

Fix for CVE-2013-4788 from http://hmarco.org/bugs/CVE-2013-4788.html

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>

diff -rupN glibc-2.17/csu/libc-start.c glibc-2.17-mangle-fix/csu/libc-start.c

--- glibc-2.17/libc/csu/libc-start.c	2012-12-25 04:02:13.000000000 +0100

+++ glibc-2.17-mangle-fix/libc/csu/libc-start.c	2013-07-10 00:13:48.000000000 +0200

@@ -38,6 +38,12 @@ extern void __pthread_initialize_minimal

    in thread local area.  */

 uintptr_t __stack_chk_guard attribute_relro;

 # endif

+

+# ifndef  THREAD_SET_POINTER_GUARD

+uintptr_t __pointer_chk_guard_local

+     attribute_relro attribute_hidden __attribute__ ((nocommon));

+# endif

+

 #endif

 #ifdef HAVE_PTR_NTHREADS

@@ -184,6 +190,14 @@ LIBC_START_MAIN (int (*main) (int, char

 # else

   __stack_chk_guard = stack_chk_guard;

 # endif

+    uintptr_t pointer_chk_guard = _dl_setup_pointer_guard (_dl_random,

+                          stack_chk_guard);

+# ifdef THREAD_SET_POINTER_GUARD

+      THREAD_SET_POINTER_GUARD (pointer_chk_guard);

+# else

+      __pointer_chk_guard_local = pointer_chk_guard;

+# endif

+

 #endif

   /* Register the destructor of the dynamic linker if there is any.  */