svn commit: r199979 - head/libexec/rtld-elf

[Colin Percival]

Author: cperciva
Date: Tue Dec  1 02:57:06 2009
New Revision: 199979
URL: http://svn.freebsd.org/changeset/base/199979

Log:
  Fix local root vulnerability.
  
  Security:	Advisory will be coming soon.
  X-MFC-After:	30 seconds

Modified:
  head/libexec/rtld-elf/rtld.c

Modified: head/libexec/rtld-elf/rtld.c
==============================================================================
--- head/libexec/rtld-elf/rtld.c	Tue Dec  1 00:42:17 2009	(r199978)
+++ head/libexec/rtld-elf/rtld.c	Tue Dec  1 02:57:06 2009	(r199979)
@@ -366,12 +366,12 @@ _rtld(Elf_Addr *sp, func_ptr_type *exit_
      * future processes to honor the potentially un-safe variables.
      */
     if (!trust) {
-        unsetenv(LD_ "PRELOAD");
-        unsetenv(LD_ "LIBMAP");
-        unsetenv(LD_ "LIBRARY_PATH");
-        unsetenv(LD_ "LIBMAP_DISABLE");
-        unsetenv(LD_ "DEBUG");
-        unsetenv(LD_ "ELF_HINTS_PATH");
+        if (unsetenv(LD_ "PRELOAD") || unsetenv(LD_ "LIBMAP") ||
+	    unsetenv(LD_ "LIBRARY_PATH") || unsetenv(LD_ "LIBMAP_DISABLE") ||
+	    unsetenv(LD_ "DEBUG") || unsetenv(LD_ "ELF_HINTS_PATH")) {
+		_rtld_error("environment corrupt; aborting");
+		die();
+	}
     }
     ld_debug = getenv(LD_ "DEBUG");
     libmap_disable = getenv(LD_ "LIBMAP_DISABLE") != NULL;