Add checks on CRYPTO_new_ex_data return value

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/996)
diff --git a/ssl/ssl_lib.c b/ssl/ssl_lib.c
index 81c4b67..e00c119 100644
--- a/ssl/ssl_lib.c
+++ b/ssl/ssl_lib.c
@@ -751,7 +751,8 @@
     if (!SSL_clear(s))
         goto err;
 
-    CRYPTO_new_ex_data(CRYPTO_EX_INDEX_SSL, s, &s->ex_data);
+    if (!CRYPTO_new_ex_data(CRYPTO_EX_INDEX_SSL, s, &s->ex_data))
+        goto err;
 
 #ifndef OPENSSL_NO_PSK
     s->psk_client_callback = ctx->psk_client_callback;
@@ -2441,7 +2442,8 @@
     if ((ret->client_CA = sk_X509_NAME_new_null()) == NULL)
         goto err;
 
-    CRYPTO_new_ex_data(CRYPTO_EX_INDEX_SSL_CTX, ret, &ret->ex_data);
+    if (!CRYPTO_new_ex_data(CRYPTO_EX_INDEX_SSL_CTX, ret, &ret->ex_data))
+        goto err;
 
     /* No compression for DTLS */
     if (!(meth->ssl3_enc->enc_flags & SSL_ENC_FLAG_DTLS))
diff --git a/ssl/ssl_sess.c b/ssl/ssl_sess.c
index d5b7fe3..3b9a9f7 100644
--- a/ssl/ssl_sess.c
+++ b/ssl/ssl_sess.c
@@ -198,8 +198,11 @@
         return NULL;
     }
 
-    CRYPTO_new_ex_data(CRYPTO_EX_INDEX_SSL_SESSION, ss, &ss->ex_data);
-
+    if (!CRYPTO_new_ex_data(CRYPTO_EX_INDEX_SSL_SESSION, ss, &ss->ex_data)) {
+        CRYPTO_THREAD_lock_free(ss->lock);
+        OPENSSL_free(ss);
+        return NULL;
+    }
     return ss;
 }