diff -up cyrus-sasl-2.1.23/lib/common.c.race cyrus-sasl-2.1.23/lib/common.c
--- cyrus-sasl-2.1.23/lib/common.c.race 2010-02-22 09:57:28.000000000 +0100
+++ cyrus-sasl-2.1.23/lib/common.c 2010-02-22 09:59:30.000000000 +0100
@@ -794,7 +794,11 @@ void sasl_dispose(sasl_conn_t **pconn)
if (result!=SASL_OK) return;
/* *pconn might have become NULL by now */
- if (! (*pconn)) return;
+ if (! (*pconn))
+ {
+ sasl_MUTEX_UNLOCK(free_mutex);
+ return;
+ }
(*pconn)->destroy_conn(*pconn);
sasl_FREE(*pconn);