From: Michael Paquier Date: Tue, 22 Jul 2025 05:00:12 +0000 (+0900) Subject: ecpg: Fix NULL pointer dereference during connection lookup X-Git-Url: http://git.postgresql.org/gitweb/?a=commitdiff_plain;h=c934d56738946fe50a413e13301d60c7a3c7318c;p=postgresql.git ecpg: Fix NULL pointer dereference during connection lookup ECPGconnect() caches established connections to the server, supporting the case of a NULL connection name when a database name is not specified by its caller. A follow-up call to ECPGget_PGconn() to get an established connection from the cached set with a non-NULL name could cause a NULL pointer dereference if a NULL connection was listed in the cache and checked for a match. At least two connections are necessary to reproduce the issue: one with a NULL name and one with a non-NULL name. Author: Aleksander Alekseev Discussion: http://postgr.es/m/CAJ7c6TNvFTPUTZQuNAoqgzaSGz-iM4XR61D7vEj5PsQXwg2RyA@mail.gmail.com Backpatch-through: 13 --- diff --git a/src/interfaces/ecpg/ecpglib/connect.c b/src/interfaces/ecpg/ecpglib/connect.c index c673a9b976d..8ab9201754f 100644 --- a/src/interfaces/ecpg/ecpglib/connect.c +++ b/src/interfaces/ecpg/ecpglib/connect.c @@ -66,7 +66,12 @@ ecpg_get_connection_nr(const char *connection_name) for (con = all_connections; con != NULL; con = con->next) { - if (strcmp(connection_name, con->name) == 0) + /* + * Check for the case of a NULL connection name, stored as such in + * the connection information by ECPGconnect() when the database + * name is not specified by its caller. + */ + if (con->name != NULL && strcmp(connection_name, con->name) == 0) break; } ret = con;