dns scavenging: ensure tombstoned node has one record

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

diff --git a/source4/dsdb/kcc/scavenge_dns_records.c b/source4/dsdb/kcc/scavenge_dns_records.c
index 6865cedd18773099e869672d2e7b7f33534ae4e1..57078695cf98ac26c2e7d3dd0851234735a1ec4e 100644 (file)
--- a/source4/dsdb/kcc/scavenge_dns_records.c
+++ b/source4/dsdb/kcc/scavenge_dns_records.c
@@ -449,7 +449,29 @@ NTSTATUS dns_delete_tombstones(TALLOC_CTX *mem_ctx,
                }
 
                for (i = 0; i < res->count; i++) {
-                       el = ldb_msg_find_element(res->msgs[i], "dnsRecord");
+                       struct ldb_message *msg = res->msgs[i];
+                       el = ldb_msg_find_element(msg, "dnsRecord");
+                       if (el == NULL) {
+                               DBG_ERR("The tombstoned dns node %s has no dns "
+                                       "records, which should not happen.\n",
+                                       ldb_dn_get_linearized(msg->dn)
+                                       );
+                               continue;
+                       }
+                       /*
+                        * Below we assume the element has one value, which we
+                        * expect because when we tombstone a node we remove
+                        * all the records except for the tombstone.
+                        */
+                       if (el->num_values != 1) {
+                               DBG_ERR("The tombstoned dns node %s has %u "
+                                       "dns records, expected one.\n",
+                                       ldb_dn_get_linearized(msg->dn),
+                                       el->num_values
+                                       );
+                               continue;
+                       }
+
                        ndr_err = ndr_pull_struct_blob(
                            el->values,
                            tmp_ctx,
@@ -491,7 +513,7 @@ NTSTATUS dns_delete_tombstones(TALLOC_CTX *mem_ctx,
                                continue;
                        }
 
-                       ret = dsdb_delete(samdb, res->msgs[i]->dn, 0);
+                       ret = dsdb_delete(samdb, msg->dn, 0);
                        if (ret != LDB_ERR_NO_SUCH_OBJECT &&
                            ret != LDB_SUCCESS) {
                                TALLOC_FREE(tmp_ctx);