Fix ex_data memory leak

Code was added in commit 62f488d that overwrite the last ex_data valye
using CRYPTO_dup_ex_data() causing a memory leak and potentially
confusing the ex_data dup() callback.

In ssl_session_dup(), new-up the ex_data before calling
CRYPTO_dup_ex_data(); all the other structures that dup ex_data have
the destination ex_data new'd before the dup.

Reviewed-by: Andy Polyakov <appro@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/3568)

diff --git a/crypto/ex_data.c b/crypto/ex_data.c
index 108a1959eacfc27b623e7d2383d9722ab945c69f..723b21b3d28181c09b1fe3410beab5e7e1ebfb0b 100644 (file)
--- a/crypto/ex_data.c
+++ b/crypto/ex_data.c
@@ -473,7 +473,14 @@ static int int_dup_ex_data(int class_index, CRYPTO_EX_DATA *to,
     if (j < mx)
         mx = j;
     if (mx > 0) {
-        if (!CRYPTO_set_ex_data(to, mx - 1, NULL))
+        /*
+         * Make sure the ex_data stack is at least |mx| elements long to avoid
+         * issues in the for loop that follows; so go get the |mx|'th element
+         * (if it does not exist CRYPTO_get_ex_data() returns NULL), and assign
+         * to itself. This is normally a no-op; but ensures the stack is the
+         * proper size
+         */
+        if (!CRYPTO_set_ex_data(to, mx - 1, CRYPTO_get_ex_data(to, mx - 1)))
             goto skip;
         storage = OPENSSL_malloc(mx * sizeof(CRYPTO_EX_DATA_FUNCS *));
         if (!storage)

diff --git a/ssl/ssl_sess.c b/ssl/ssl_sess.c
index f50f5142126f80e19a599ed8b8380f203a9aa24a..23dd3e7a01c33ca87db5020731bead6f097bcd4f 100644 (file)
--- a/ssl/ssl_sess.c
+++ b/ssl/ssl_sess.c
@@ -261,7 +261,6 @@ SSL_SESSION *ssl_session_dup(SSL_SESSION *src, int ticket)
 #ifndef OPENSSL_NO_SRP
     dest->srp_username = NULL;
 #endif
-    memset(&dest->ex_data, 0, sizeof(dest->ex_data));
 
     /* We deliberately don't copy the prev and next pointers */
     dest->prev = NULL;
@@ -275,6 +274,9 @@ SSL_SESSION *ssl_session_dup(SSL_SESSION *src, int ticket)
     if (src->peer != NULL)
         CRYPTO_add(&src->peer->references, 1, CRYPTO_LOCK_X509);
 
+    if (!CRYPTO_new_ex_data(CRYPTO_EX_INDEX_SSL_SESSION, dest, &dest->ex_data))
+        goto err;
+
 #ifndef OPENSSL_NO_PSK
     if (src->psk_identity_hint) {
         dest->psk_identity_hint = BUF_strdup(src->psk_identity_hint);
@@ -325,7 +327,7 @@ SSL_SESSION *ssl_session_dup(SSL_SESSION *src, int ticket)
     }
 # endif
 
-    if (ticket != 0) {
+    if (ticket != 0 && src->tlsext_tick != NULL) {
         dest->tlsext_tick = BUF_memdup(src->tlsext_tick, src->tlsext_ticklen);
         if(dest->tlsext_tick == NULL)
             goto err;