1 files changed, 41 insertions, 18 deletions

diff --git a/lib/openpam_dynamic.c b/lib/openpam_dynamic.c
index 084408e..d44174f 100644
--- a/lib/openpam_dynamic.c
+++ b/lib/openpam_dynamic.c
@@ -1,6 +1,6 @@
 /*-
  * Copyright (c) 2002-2003 Networks Associates Technology, Inc.
- * Copyright (c) 2004-2007 Dag-Erling Smørgrav
+ * Copyright (c) 2004-2011 Dag-Erling Smørgrav
  * All rights reserved.
  *
  * This software was developed for the FreeBSD Project by ThinkSec AS and
@@ -32,13 +32,19 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $Id: openpam_dynamic.c 408 2007-12-21 11:36:24Z des $
+ * $Id: openpam_dynamic.c 502 2011-12-18 13:59:22Z des $
  */
 
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
 #include <dlfcn.h>
+#include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <unistd.h>
 
 #include <security/pam_appl.h>
 
@@ -51,21 +57,35 @@
 /*
  * OpenPAM internal
  *
+ * Perform sanity checks and attempt to load a module
+ */
+
+static void *
+try_dlopen(const char *modfn)
+{
+
+	if (openpam_check_path_owner_perms(modfn) != 0)
+		return (NULL);
+	return (dlopen(modfn, RTLD_NOW));
+}
+    
+/*
+ * OpenPAM internal
+ *
  * Locate a dynamically linked module
  */
 
 pam_module_t *
 openpam_dynamic(const char *path)
 {
+	const pam_module_t *dlmodule;
 	pam_module_t *module;
 	const char *prefix;
 	char *vpath;
 	void *dlh;
-	int i;
+	int i, serrno;
 
 	dlh = NULL;
-	if ((module = calloc(1, sizeof *module)) == NULL)
-		goto buf_err;
 
 	/* Prepend the standard prefix if not an absolute pathname. */
 	if (path[0] != '/')
@@ -75,33 +95,36 @@ openpam_dynamic(const char *path)
 
 	/* try versioned module first, then unversioned module */
 	if (asprintf(&vpath, "%s%s.%d", prefix, path, LIB_MAJ) < 0)
-		goto buf_err;
-	if ((dlh = dlopen(vpath, RTLD_NOW)) == NULL) {
-		openpam_log(PAM_LOG_DEBUG, "%s: %s", vpath, dlerror());
+		goto err;
+	if ((dlh = try_dlopen(vpath)) == NULL && errno == ENOENT) {
 		*strrchr(vpath, '.') = '\0';
-		if ((dlh = dlopen(vpath, RTLD_NOW)) == NULL) {
-			openpam_log(PAM_LOG_DEBUG, "%s: %s", vpath, dlerror());
-			FREE(vpath);
-			FREE(module);
-			return (NULL);
-		}
+		dlh = try_dlopen(vpath);
 	}
+	serrno = errno;
 	FREE(vpath);
+	errno = serrno;
+	if (dlh == NULL)
+		goto err;
+	if ((module = calloc(1, sizeof *module)) == NULL)
+		goto buf_err;
 	if ((module->path = strdup(path)) == NULL)
 		goto buf_err;
 	module->dlh = dlh;
+	dlmodule = dlsym(dlh, "_pam_module");
 	for (i = 0; i < PAM_NUM_PRIMITIVES; ++i) {
-		module->func[i] = (pam_func_t)dlsym(dlh, _pam_sm_func_name[i]);
+		module->func[i] = dlmodule ? dlmodule->func[i] :
+		    (pam_func_t)dlsym(dlh, pam_sm_func_name[i]);
 		if (module->func[i] == NULL)
 			openpam_log(PAM_LOG_DEBUG, "%s: %s(): %s",
-			    path, _pam_sm_func_name[i], dlerror());
+			    path, pam_sm_func_name[i], dlerror());
 	}
 	return (module);
- buf_err:
-	openpam_log(PAM_LOG_ERROR, "%m");
+buf_err:
 	if (dlh != NULL)
 		dlclose(dlh);
 	FREE(module);
+err:
+	openpam_log(PAM_LOG_ERROR, "%m");
 	return (NULL);
 }