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-rw-r--r--elf/dl-load.c70
1 files changed, 57 insertions, 13 deletions
diff --git a/elf/dl-load.c b/elf/dl-load.c
index 7dc6d91..6a3d919 100644
--- a/elf/dl-load.c
+++ b/elf/dl-load.c
@@ -1,5 +1,5 @@
/* _dl_map_object -- Map in a shared object's segments from the file.
- Copyright (C) 1995, 1996 Free Software Foundation, Inc.
+ Copyright (C) 1995, 1996, 1997 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
@@ -409,7 +409,8 @@ _dl_map_object_from_fd (char *name, int fd, char *realname,
static int
open_path (const char *name, size_t namelen,
const char *dirpath,
- char **realname)
+ char **realname,
+ const char *trusted_dirs[])
{
char *buf;
const char *p;
@@ -426,13 +427,42 @@ open_path (const char *name, size_t namelen,
do
{
size_t buflen;
+ size_t this_len;
dirpath = p;
p = strpbrk (dirpath, ":;");
if (p == NULL)
p = strchr (dirpath, '\0');
- if (p == dirpath)
+ this_len = p - dirpath;
+
+ /* When we run a setuid program we do not accept any directory. */
+ if (__libc_enable_secure)
+ {
+ /* All trusted directory must be complete name. */
+ if (dirpath[0] != '/')
+ continue;
+
+ /* If we got a list of trusted directories only accept one
+ of these. */
+ if (trusted_dirs != NULL)
+ {
+ const char **trust = trusted_dirs;
+
+ while (*trust != NULL)
+ if (memcmp (dirpath, *trust, this_len) == 0
+ && (*trust)[this_len] == '\0')
+ break;
+ else
+ ++trust;
+
+ /* If directory is not trusted, ignore this directory. */
+ if (*trust == NULL)
+ continue;
+ }
+ }
+
+ if (this_len == 0)
{
/* Two adjacent colons, or a colon at the beginning or the end of
the path means to search the current directory. */
@@ -442,10 +472,10 @@ open_path (const char *name, size_t namelen,
else
{
/* Construct the pathname to try. */
- (void) memcpy (buf, dirpath, p - dirpath);
- buf[p - dirpath] = '/';
- (void) memcpy (&buf[(p - dirpath) + 1], name, namelen);
- buflen = p - dirpath + 1 + namelen;
+ (void) memcpy (buf, dirpath, this_len);
+ buf[this_len] = '/';
+ (void) memcpy (&buf[this_len + 1], name, namelen);
+ buflen = this_len + 1 + namelen;
}
fd = __open (buf, O_RDONLY);
@@ -508,9 +538,9 @@ _dl_map_object (struct link_map *loader, const char *name, int type,
size_t namelen = strlen (name) + 1;
- inline void trypath (const char *dirpath)
+ inline void trypath (const char *dirpath, const char *trusted[])
{
- fd = open_path (name, namelen, dirpath, &realname);
+ fd = open_path (name, namelen, dirpath, &realname, trusted);
}
fd = -1;
@@ -521,16 +551,24 @@ _dl_map_object (struct link_map *loader, const char *name, int type,
if (l && l->l_info[DT_RPATH])
trypath ((const char *) (l->l_addr +
l->l_info[DT_STRTAB]->d_un.d_ptr +
- l->l_info[DT_RPATH]->d_un.d_val));
+ l->l_info[DT_RPATH]->d_un.d_val), NULL);
/* If dynamically linked, try the DT_RPATH of the executable itself. */
l = _dl_loaded;
if (fd == -1 && l && l->l_type != lt_loaded && l->l_info[DT_RPATH])
trypath ((const char *) (l->l_addr +
l->l_info[DT_STRTAB]->d_un.d_ptr +
- l->l_info[DT_RPATH]->d_un.d_val));
+ l->l_info[DT_RPATH]->d_un.d_val), NULL);
/* Try an environment variable (unless setuid). */
if (fd == -1 && ! __libc_enable_secure)
- trypath (getenv ("LD_LIBRARY_PATH"));
+ {
+ static const char *trusted_dirs[] =
+ {
+#include "trusted-dirs.h"
+ NULL
+ };
+
+ trypath (getenv ("LD_LIBRARY_PATH"), trusted_dirs);
+ }
if (fd == -1)
{
/* Check the list of libraries in the file /etc/ld.so.cache,
@@ -555,7 +593,7 @@ _dl_map_object (struct link_map *loader, const char *name, int type,
if (fd == -1)
{
extern const char *_dl_rpath; /* Set in rtld.c. */
- trypath (_dl_rpath);
+ trypath (_dl_rpath, NULL);
}
}
else
@@ -590,6 +628,7 @@ _dl_map_object (struct link_map *loader, const char *name, int type,
are only interested in the list of libraries this isn't
so severe. Fake an entry with all the information we
have (in fact only the name). */
+ static const ElfW(Symndx) dummy_bucket = STN_UNDEF;
/* Enter the new object in the list of loaded objects. */
if ((name_copy = local_strdup (name)) == NULL
@@ -599,6 +638,11 @@ _dl_map_object (struct link_map *loader, const char *name, int type,
/* We use an opencount of 0 as a sign for the faked entry. */
l->l_opencount = 0;
l->l_reserved = 0;
+ l->l_buckets = &dummy_bucket;
+ l->l_nbuckets = 1;
+ l->l_relocated = 1;
+
+ return l;
}
else
_dl_signal_error (errno, name, "cannot open shared object file");