s3: Fix a crash in group_mapping.ldb->tdb conversion

When we find a group_mapping.ldb entry without a comment, the upgrade code
would have crashed with a NULL dereference

Autobuild-User: Volker Lendecke <vlendec@samba.org>
Autobuild-Date: Mon Nov 28 12:24:08 CET 2011 on sn-devel-104

diff --git a/source3/groupdb/mapping_tdb.c b/source3/groupdb/mapping_tdb.c
index 394a2f0b223eb78b21124a593742e03314767f08..1dea9e482e5826ce26bf51940abd547ef8d00b08 100644 (file)
--- a/source3/groupdb/mapping_tdb.c
+++ b/source3/groupdb/mapping_tdb.c
@@ -1006,6 +1006,19 @@ static int convert_ldb_record(TDB_CONTEXT *ltdb, TDB_DATA key,
                TALLOC_FREE(name);
        }
 
+       if (map->nt_name == NULL) {
+               errno = EIO;
+               goto failed;
+       }
+
+       if (map->comment == NULL) {
+               map->comment = talloc_strdup(map, "");
+       }
+       if (map->comment == NULL) {
+               errno = ENOMEM;
+               goto failed;
+       }
+
        if (!add_mapping_entry(map, 0)) {
                errno = EIO;
                goto failed;