CVE-2018-16851 ldap_server: Check ret before manipulating blob

In the case of hitting the talloc ~256MB limit, this causes a crash in the server. Note that you would actually need to load >256MB of data into the LDAP. Although there is some generated/hidden data which would help you reach that limit (descriptors and RMD blobs). BUG: https://bugzilla.samba.org/show_bug.cgi?id=13674 Signed-off-by: Garming Sam <[email protected]> Reviewed-by: Andrew Bartlett <[email protected]>
anodos325 · Nov 28, 2018 · d2c98ab · d2c98ab
1 parent c835e27
commit d2c98ab
Showing 1 changed file with 2 additions and 2 deletions.
diff --git a/source4/ldap_server/ldap_server.c b/source4/ldap_server/ldap_server.c
@@ -690,13 +690,13 @@ static void ldapsrv_call_writev_start(struct ldapsrv_call *call)
 		ret = data_blob_append(call, &blob, b.data, b.length);
 		data_blob_free(&b);
 
-		talloc_set_name_const(blob.data, "Outgoing, encoded LDAP packet");
-
 		if (!ret) {
 			ldapsrv_terminate_connection(conn, "data_blob_append failed");
 			return;
 		}
 
+		talloc_set_name_const(blob.data, "Outgoing, encoded LDAP packet");
+
 		DLIST_REMOVE(call->replies, call->replies);
 	}