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authorUlrich Drepper <drepper@redhat.com>2004-03-05 03:47:38 +0000
committerUlrich Drepper <drepper@redhat.com>2004-03-05 03:47:38 +0000
commitf213ef02800eba75bcc5d4c5aaa5a19f5f6235fe (patch)
tree29d35cb5a33905879bb52abd0eca82aa73a87767 /elf
parent6fefb4e0b1695a4f7d0d18be6c04472bb3995071 (diff)
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Update.
2004-03-04 Ulrich Drepper <drepper@redhat.com> * elf/dl-open.c (dl_open_worker): Check that _dl_open is called from the right place.
Diffstat (limited to 'elf')
-rw-r--r--elf/dl-open.c71
1 files changed, 64 insertions, 7 deletions
diff --git a/elf/dl-open.c b/elf/dl-open.c
index fcda376..4a322e2 100644
--- a/elf/dl-open.c
+++ b/elf/dl-open.c
@@ -1,5 +1,5 @@
/* Load a shared object at runtime, relocate it, and run its initializer.
- Copyright (C) 1996-2001, 2002, 2003 Free Software Foundation, Inc.
+ Copyright (C) 1996-2001, 2002, 2003, 2004 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
@@ -30,6 +30,7 @@
#include <bits/libc-lock.h>
#include <ldsodefs.h>
#include <bp-sym.h>
+#include <gnu/lib-names.h>
#include <dl-dst.h>
@@ -66,7 +67,10 @@ struct dl_open_args
{
const char *file;
int mode;
- const void *caller;
+ /* This is the caller of the dlopen() function. */
+ const void *caller_dlopen;
+ /* This is the caller if _dl_open(). */
+ const void *caller_dl_open;
struct link_map *map;
};
@@ -152,6 +156,52 @@ add_to_global (struct link_map *new)
}
+#ifdef SHARED
+static int
+internal_function
+check_libc_caller (const void *caller)
+{
+ static const char expected1[] = LIBC_SO;
+ static const char expected2[] = LIBDL_SO;
+
+ /* If we already know the address ranges, just test. */
+ static const void *expected1_from;
+ static const void *expected1_to;
+ static const void *expected2_from;
+ static const void *expected2_to;
+
+ if (expected1_from == NULL)
+ {
+ /* The only other DSO which is allowed to call these functions is
+ libdl. Find the address range containing the caller. */
+ struct link_map *l;
+
+ for (l = GL(dl_loaded); l != NULL; l = l->l_next)
+ if (_dl_name_match_p (expected1, l))
+ {
+ expected1_from = (const void *) l->l_map_start;
+ expected1_to = (const void *) l->l_map_end;
+ }
+ else if (_dl_name_match_p (expected2, l))
+ {
+ expected2_from = (const void *) l->l_map_start;
+ expected2_to = (const void *) l->l_map_end;
+ }
+
+ assert (expected1_from != NULL);
+ }
+
+ /* When there would be more than two expected caller we could use an
+ array for the values but for now this is cheaper. */
+ if ((caller >= expected1_from && caller < expected1_to)
+ || (caller >= expected2_from && caller < expected2_to))
+ return 0;
+
+ return 1;
+}
+#endif
+
+
static void
dl_open_worker (void *a)
{
@@ -166,11 +216,17 @@ dl_open_worker (void *a)
bool any_tls;
#endif
+#ifdef SHARED
+ /* Check whether _dl_open() has been called from a valid DSO. */
+ if (check_libc_caller (args->caller_dl_open) != 0)
+ _dl_signal_error (0, "dlopen", NULL, N_("invalid caller"));
+#endif
+
/* Maybe we have to expand a DST. */
dst = strchr (file, '$');
if (__builtin_expect (dst != NULL, 0))
{
- const void *caller = args->caller;
+ const void *caller_dlopen = args->caller_dlopen;
size_t len = strlen (file);
size_t required;
struct link_map *call_map;
@@ -185,8 +241,8 @@ dl_open_worker (void *a)
/* We have to find out from which object the caller is calling. */
call_map = NULL;
for (l = GL(dl_loaded); l; l = l->l_next)
- if (caller >= (const void *) l->l_map_start
- && caller < (const void *) l->l_map_end)
+ if (caller_dlopen >= (const void *) l->l_map_start
+ && caller_dlopen < (const void *) l->l_map_end)
{
/* There must be exactly one DSO for the range of the virtual
memory. Otherwise something is really broken. */
@@ -484,7 +540,7 @@ dl_open_worker (void *a)
void *
internal_function
-_dl_open (const char *file, int mode, const void *caller)
+_dl_open (const char *file, int mode, const void *caller_dlopen)
{
struct dl_open_args args;
const char *objname;
@@ -500,7 +556,8 @@ _dl_open (const char *file, int mode, const void *caller)
args.file = file;
args.mode = mode;
- args.caller = caller;
+ args.caller_dlopen = caller_dlopen;
+ args.caller_dl_open = RETURN_ADDRESS (0);
args.map = NULL;
errcode = _dl_catch_error (&objname, &errstring, dl_open_worker, &args);