CVE-2020-25722 s4/dsdb/samldb: samldb_fsmo_role_owner_check checks values

BUG: https://bugzilla.samba.org/show_bug.cgi?id=14876

Signed-off-by: Douglas Bagnall <douglas.bagnall@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>

diff --git a/source4/dsdb/samdb/ldb_modules/samldb.c b/source4/dsdb/samdb/ldb_modules/samldb.c
index 80ca1e3afc08451f7cee00ac40a17557761ef4a6..d75277b3853630038a1ec3cf11fba0d4721645c9 100644 (file)
--- a/source4/dsdb/samdb/ldb_modules/samldb.c
+++ b/source4/dsdb/samdb/ldb_modules/samldb.c
@@ -4302,9 +4302,15 @@ static int samldb_fsmo_role_owner_check(struct samldb_ctx *ac)
        struct ldb_dn *res_dn;
        struct ldb_result *res;
        int ret;
+       ret = dsdb_get_expected_new_values(ac,
+                                          ac->msg,
+                                          "fSMORoleOwner",
+                                          &el,
+                                          ac->req->operation);
+       if (ret != LDB_SUCCESS) {
+               return ret;
+       }
 
-       el = dsdb_get_single_valued_attr(ac->msg, "fSMORoleOwner",
-                                        ac->req->operation);
        if (el == NULL) {
                /* we are not affected */
                return LDB_SUCCESS;