diff options
Diffstat (limited to 'elf')
| -rw-r--r-- | elf/dl-open.c | 71 |
1 files changed, 64 insertions, 7 deletions
diff --git a/elf/dl-open.c b/elf/dl-open.c index fcda37676d..4a322e28e8 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); |