Fix invalid memory access in do_lookup_x.

[BZ #13579] Do not free l_initfini and allow it to be reused
on subsequent dl_open calls for the same library. This fixes
the invalid memory access in do_lookup_x when the previously
free'd l_initfini was accessed through l_searchlist when a
library had been opened for the second time.

4 files changed, 15 insertions, 18 deletions

diff --git a/elf/dl-close.c b/elf/dl-close.c
index d232294665..a250ea5e3e 100644
--- a/elf/dl-close.c
+++ b/elf/dl-close.c
@@ -1,5 +1,5 @@
 /* Close a shared object opened by `_dl_open'.
-   Copyright (C) 1996-2007, 2009, 2010, 2011 Free Software Foundation, Inc.
+   Copyright (C) 1996-2012 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -118,17 +118,8 @@ _dl_close_worker (struct link_map *map)
   if (map->l_direct_opencount > 0 || map->l_type != lt_loaded
       || dl_close_state != not_pending)
     {
-      if (map->l_direct_opencount == 0)
-	{
-	  if (map->l_type == lt_loaded)
-	    dl_close_state = rerun;
-	  else if (map->l_type == lt_library)
-	    {
-	      struct link_map **oldp = map->l_initfini;
-	      map->l_initfini = map->l_orig_initfini;
-	      _dl_scope_free (oldp);
-	    }
-	}
+      if (map->l_direct_opencount == 0 && map->l_type == lt_loaded)
+	dl_close_state = rerun;
 
       /* There are still references to this object.  Do nothing more.  */
       if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_FILES, 0))
diff --git a/elf/dl-deps.c b/elf/dl-deps.c
index 69aec461fb..2ae496d7b5 100644
--- a/elf/dl-deps.c
+++ b/elf/dl-deps.c
@@ -1,6 +1,5 @@
 /* Load the dependencies of a mapped object.
-   Copyright (C) 1996-2003, 2004-2007, 2010-2012
-   Free Software Foundation, Inc.
+   Copyright (C) 1996-2012 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -488,6 +487,7 @@ _dl_map_object_deps (struct link_map *map,
 		  nneeded * sizeof needed[0]);
 	  atomic_write_barrier ();
 	  l->l_initfini = l_initfini;
+	  l->l_free_initfini = 1;
 	}
 
       /* If we have no auxiliary objects just go on to the next map.  */
@@ -688,6 +688,7 @@ Filters not supported with LD_TRACE_PRELINKING"));
   l_initfini[nlist] = NULL;
   atomic_write_barrier ();
   map->l_initfini = l_initfini;
+  map->l_free_initfini = 1;
   if (l_reldeps != NULL)
     {
       atomic_write_barrier ();
@@ -696,7 +697,7 @@ Filters not supported with LD_TRACE_PRELINKING"));
       _dl_scope_free (old_l_reldeps);
     }
   if (old_l_initfini != NULL)
-      map->l_orig_initfini = old_l_initfini;
+    _dl_scope_free (old_l_initfini);
 
   if (errno_reason)
     _dl_signal_error (errno_reason == -1 ? 0 : errno_reason, objname,
diff --git a/elf/dl-libc.c b/elf/dl-libc.c
index a58e2164f6..af2e663737 100644
--- a/elf/dl-libc.c
+++ b/elf/dl-libc.c
@@ -1,6 +1,5 @@
 /* Handle loading and unloading shared objects for internal libc purposes.
-   Copyright (C) 1999-2002,2004-2006,2009,2010,2011
-   Free Software Foundation, Inc.
+   Copyright (C) 1999-2012 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Zack Weinberg <zack@rabi.columbia.edu>, 1999.
 
@@ -269,13 +268,13 @@ libc_freeres_fn (free_mem)
 
   for (Lmid_t ns = 0; ns < GL(dl_nns); ++ns)
     {
-      /* Remove all additional names added to the objects.  */
       for (l = GL(dl_ns)[ns]._ns_loaded; l != NULL; l = l->l_next)
 	{
 	  struct libname_list *lnp = l->l_libname->next;
 
 	  l->l_libname->next = NULL;
 
+	  /* Remove all additional names added to the objects.  */
 	  while (lnp != NULL)
 	    {
 	      struct libname_list *old = lnp;
@@ -283,6 +282,10 @@ libc_freeres_fn (free_mem)
 	      if (! old->dont_free)
 		free (old);
 	    }
+
+	  /* Free the initfini dependency list.  */
+	  if (l->l_free_initfini)
+	    free (l->l_initfini);
 	}
 
       if (__builtin_expect (GL(dl_ns)[ns]._ns_global_scope_alloc, 0) != 0
diff --git a/elf/rtld.c b/elf/rtld.c
index a5b0ab9815..6bcf224c49 100644
--- a/elf/rtld.c
+++ b/elf/rtld.c
@@ -2292,6 +2292,8 @@ ERROR: ld.so: object '%s' cannot be loaded as audit interface: %s; ignored.\n",
 	      lnp->dont_free = 1;
 	      lnp = lnp->next;
 	    }
+	  /* Also allocated with the fake malloc().  */
+	  l->l_free_initfini = 0;
 
 	  if (l != &GL(dl_rtld_map))
 	    _dl_relocate_object (l, l->l_scope, GLRO(dl_lazy) ? RTLD_LAZY : 0,