File dl-init-paths-overflow.patch of Package glibc.21322

2017-12-18  Dmitry V. Levin  <ldv@altlinux.org>

	[BZ #22627]
	* elf/dl-load.c (_dl_init_paths): Remove _dl_dst_substitute preparatory
	code and invocation.

2017-12-14  Florian Weimer  <fweimer@redhat.com>

	[BZ #22607]
	CVE-2017-1000409
	* elf/dl-load.c (_dl_init_paths): Compute number of components in
	the expanded path string.

2017-12-14  Florian Weimer  <fweimer@redhat.com>

	[BZ #22606]
	CVE-2017-1000408
	* elf/dl-load.c (system_dirs): Update comment.
	(_dl_init_paths): Use nsystem_dirs_len to compute the array size.

Index: glibc-2.26/elf/dl-load.c
===================================================================
--- glibc-2.26.orig/elf/dl-load.c
+++ glibc-2.26/elf/dl-load.c
@@ -103,7 +103,9 @@ static size_t ncapstr attribute_relro;
 static size_t max_capstrlen attribute_relro;
 
 
-/* Get the generated information about the trusted directories.  */
+/* Get the generated information about the trusted directories.  Use
+   an array of concatenated strings to avoid relocations.  See
+   gen-trusted-dirs.awk.  */
 #include "trusted-dirs.h"
 
 static const char system_dirs[] = SYSTEM_DIRS;
@@ -688,9 +690,8 @@ _dl_init_paths (const char *llp)
 		 + ncapstr * sizeof (enum r_dir_status))
 		/ sizeof (struct r_search_path_elem));
 
-  rtld_search_dirs.dirs[0] = (struct r_search_path_elem *)
-    malloc ((sizeof (system_dirs) / sizeof (system_dirs[0]))
-	    * round_size * sizeof (struct r_search_path_elem));
+  rtld_search_dirs.dirs[0] = malloc (nsystem_dirs_len * round_size
+				     * sizeof (*rtld_search_dirs.dirs[0]));
   if (rtld_search_dirs.dirs[0] == NULL)
     {
       errstring = N_("cannot create cache for search path");
@@ -776,37 +777,14 @@ _dl_init_paths (const char *llp)
 
   if (llp != NULL && *llp != '\0')
     {
-      size_t nllp;
-      const char *cp = llp;
-      char *llp_tmp;
-
-#ifdef SHARED
-      /* Expand DSTs.  */
-      size_t cnt = DL_DST_COUNT (llp, 1);
-      if (__glibc_likely (cnt == 0))
-	llp_tmp = strdupa (llp);
-      else
-	{
-	  /* Determine the length of the substituted string.  */
-	  size_t total = DL_DST_REQUIRED (l, llp, strlen (llp), cnt);
-
-	  /* Allocate the necessary memory.  */
-	  llp_tmp = (char *) alloca (total + 1);
-	  llp_tmp = _dl_dst_substitute (l, llp, llp_tmp, 1);
-	}
-#else
-      llp_tmp = strdupa (llp);
-#endif
+      char *llp_tmp = strdupa (llp);
 
       /* Decompose the LD_LIBRARY_PATH contents.  First determine how many
 	 elements it has.  */
-      nllp = 1;
-      while (*cp)
-	{
-	  if (*cp == ':' || *cp == ';')
-	    ++nllp;
-	  ++cp;
-	}
+      size_t nllp = 1;
+      for (const char *cp = llp_tmp; *cp != '\0'; ++cp)
+	if (*cp == ':' || *cp == ';')
+	  ++nllp;
 
       env_path_list.dirs = (struct r_search_path_elem **)
 	malloc ((nllp + 1) * sizeof (struct r_search_path_elem *));