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 <aleksander@tigerdata.com>
Discussion: https://postgr.es/m/CAJ7c6TNvFTPUTZQuNAoqgzaSGz-iM4XR61D7vEj5PsQXwg2RyA@mail.gmail.com
Backpatch-through: 13
This commit is contained in:
Michael Paquier
2025-07-22 14:00:12 +09:00
parent ab13b7a8c7
commit c934d56738

View File

@ -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;