Fix bug 8920, null dereference

Description: Avoid null dereference in initialize_password_db()
 When initialize_password_db() is called with reload=True, it's assumed that
 the free_private_data member of pdb_methods is non-null.  This is not
 necessarily the case, as the tdb backend has no private data and therefore
 no free function.  Check to see if we have private data that needs freed
 before calling.
Author: Steve Langasek <steve.langasek@ubuntu.com>
Bug-Ubuntu: https://bugs.launchpad.net/bugs/829221

diff --git a/source3/passdb/pdb_interface.c b/source3/passdb/pdb_interface.c
index 36d5aaa01a7586739a7752a3f7846e07b8684871..3c11016f06fab937d2a160da92e91d4259955fcc 100644 (file)
--- a/source3/passdb/pdb_interface.c
+++ b/source3/passdb/pdb_interface.c
@@ -184,7 +184,9 @@ static struct pdb_methods *pdb_get_methods_reload( bool reload )
        static struct pdb_methods *pdb = NULL;
 
        if ( pdb && reload ) {
-               pdb->free_private_data( &(pdb->private_data) );
+               if (pdb->free_private_data != NULL) {
+                       pdb->free_private_data( &(pdb->private_data) );
+               }
                if ( !NT_STATUS_IS_OK( make_pdb_method_name( &pdb, lp_passdb_backend() ) ) ) {
                        char *msg = NULL;
                        if (asprintf(&msg, "pdb_get_methods_reload: "