From 3309a6799665fab6fb9c61aa50897745908bdc30 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Manuel=20P=C3=A9gouri=C3=A9-Gonnard?=
 <manuel.pegourie-gonnard@arm.com>
Date: Mon, 15 Jul 2019 10:31:11 +0200
Subject: [PATCH] Fix memory leak in client/server2

context_buf was never free()d. Moreover, since we want to free it on error
paths as well, and even properly zeroize it in order to demonstrate good
memory hygiene, we need to make it and its length main()-scoped.
---
 programs/ssl/ssl_client2.c | 15 ++++++++++++++-
 programs/ssl/ssl_server2.c | 16 +++++++++++++++-
 2 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/programs/ssl/ssl_client2.c b/programs/ssl/ssl_client2.c
index 37b047cc4..4efd73f2c 100644
--- a/programs/ssl/ssl_client2.c
+++ b/programs/ssl/ssl_client2.c
@@ -1083,6 +1083,10 @@ int main( int argc, char *argv[] )
 #endif
     char *p, *q;
     const int *list;
+#if defined(MBEDTLS_SSL_CONTEXT_SERIALIZATION)
+    unsigned char *context_buf = NULL;
+    size_t context_buf_len;
+#endif
 #if defined(MBEDTLS_SSL_EXPORT_KEYS)
     unsigned char eap_tls_keymaterial[16];
     unsigned char eap_tls_iv[8];
@@ -2922,7 +2926,6 @@ send_request:
     if( opt.serialize != 0 )
     {
         size_t buf_len;
-        unsigned char *context_buf = NULL;
 
         mbedtls_printf( "  . Serializing live connection..." );
 
@@ -2942,6 +2945,7 @@ send_request:
 
             goto exit;
         }
+        context_buf_len = buf_len;
 
         if( ( ret = mbedtls_ssl_context_save( &ssl, context_buf,
                                               buf_len, &buf_len ) ) != 0 )
@@ -3012,6 +3016,10 @@ send_request:
             goto exit;
         }
 
+        mbedtls_free( context_buf );
+        context_buf = NULL;
+        context_buf_len = 0;
+
         mbedtls_printf( " ok\n" );
     }
 #endif /* MBEDTLS_SSL_CONTEXT_SERIALIZATION */
@@ -3152,6 +3160,11 @@ exit:
     if( session_data != NULL )
         mbedtls_platform_zeroize( session_data, session_data_len );
     mbedtls_free( session_data );
+#if defined(MBEDTLS_SSL_CONTEXT_SERIALIZATION)
+    if( context_buf != NULL )
+        mbedtls_platform_zeroize( context_buf, context_buf_len );
+    mbedtls_free( context_buf );
+#endif
 
 #if defined(MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED) && \
     defined(MBEDTLS_USE_PSA_CRYPTO)
diff --git a/programs/ssl/ssl_server2.c b/programs/ssl/ssl_server2.c
index 5b7d17379..dbdb29959 100644
--- a/programs/ssl/ssl_server2.c
+++ b/programs/ssl/ssl_server2.c
@@ -1727,6 +1727,10 @@ int main( int argc, char *argv[] )
     size_t cid_len = 0;
     size_t cid_renego_len = 0;
 #endif
+#if defined(MBEDTLS_SSL_CONTEXT_SERIALIZATION)
+    unsigned char *context_buf = NULL;
+    size_t context_buf_len;
+#endif
 
     int i;
     char *p, *q;
@@ -3933,7 +3937,6 @@ data_exchange:
     if( opt.serialize != 0 )
     {
         size_t buf_len;
-        unsigned char *context_buf = NULL;
 
         mbedtls_printf( "  . Serializing live connection..." );
 
@@ -3953,6 +3956,7 @@ data_exchange:
 
             goto exit;
         }
+        context_buf_len = buf_len;
 
         if( ( ret = mbedtls_ssl_context_save( &ssl, context_buf,
                                               buf_len, &buf_len ) ) != 0 )
@@ -4044,6 +4048,10 @@ data_exchange:
             goto exit;
         }
 
+        mbedtls_free( context_buf );
+        context_buf = NULL;
+        context_buf_len = 0;
+
         mbedtls_printf( " ok\n" );
     }
 #endif /* MBEDTLS_SSL_CONTEXT_SERIALIZATION */
@@ -4155,6 +4163,12 @@ exit:
 
     mbedtls_free( buf );
 
+#if defined(MBEDTLS_SSL_CONTEXT_SERIALIZATION)
+    if( context_buf != NULL )
+        mbedtls_platform_zeroize( context_buf, context_buf_len );
+    mbedtls_free( context_buf );
+#endif
+
 #if defined(MBEDTLS_MEMORY_BUFFER_ALLOC_C)
 #if defined(MBEDTLS_MEMORY_DEBUG)
     mbedtls_memory_buffer_alloc_status();