1 files changed, 14 insertions, 3 deletions

diff --git a/src/lib/libssl/ssl_lib.c b/src/lib/libssl/ssl_lib.c
index ab172aeaec..4bc4ce5b3a 100644
--- a/src/lib/libssl/ssl_lib.c
+++ b/src/lib/libssl/ssl_lib.c
@@ -1405,13 +1405,24 @@ void SSL_CTX_free(SSL_CTX *a)
                 abort(); /* ok */
                 }
 #endif
-        CRYPTO_free_ex_data(CRYPTO_EX_INDEX_SSL_CTX, a, &a->ex_data);
 
+        /*
+         * Free internal session cache. However: the remove_cb() may reference
+         * the ex_data of SSL_CTX, thus the ex_data store can only be removed
+         * after the sessions were flushed.
+         * As the ex_data handling routines might also touch the session cache,
+         * the most secure solution seems to be: empty (flush) the cache, then
+         * free ex_data, then finally free the cache.
+         * (See ticket [openssl.org #212].)
+         */
         if (a->sessions != NULL)
-                {
                 SSL_CTX_flush_sessions(a,0);
+
+        CRYPTO_free_ex_data(CRYPTO_EX_INDEX_SSL_CTX, a, &a->ex_data);
+
+        if (a->sessions != NULL)
                 lh_free(a->sessions);
-                }
+
         if (a->cert_store != NULL)
                 X509_STORE_free(a->cert_store);
         if (a->cipher_list != NULL)