[PATCH] Fix rtld segfault in SUID/SGID binaries

[Jakub Jelinek <jakub at redhat dot com>]

Hi!

If a user runs a suid/sgid program with LD_LIBRARY_PATH set, so that all
fields of it go away because they are insecure, open_path segfaults because
it does not expect the path list to be empty.
We can either fix open_path to use a while () {} loop instead of do {} while (),
or make sure env_path_list is killed if it has 0 list. I don't think
RPATH/RUNPATH can have 0 elements, so IMHO it is better not to slow down
things for all 3 cases but only for LD_LIBRARY_PATH.

2000-05-22  Jakub Jelinek  <jakub@redhat.com>

	* elf/dl-load.c (_dl_init_paths): If env_path_list has 0 elements,
	free it and set to (void *) -1.

--- libc/elf/dl-load.c.jj	Tue May  9 13:47:25 2000
+++ libc/elf/dl-load.c	Mon May 22 14:43:19 2000
@@ -636,6 +636,11 @@ _dl_init_paths (const char *llp)
 
       (void) fillin_rpath (local_strdup (llp), env_path_list, ":;",
 			   __libc_enable_secure, "LD_LIBRARY_PATH", NULL);
+      if (env_path_list[0] == NULL)
+	{
+	  free (env_path_list);
+	  env_path_list = (void *) -1;
+	}
     }
   else
     env_path_list = (void *) -1;

	Jakub