diff --git a/ChangeLog b/ChangeLog index d287c5f559..78e9ebf043 100644 --- a/ChangeLog +++ b/ChangeLog @@ -10,6 +10,8 @@ Bugfix * Add ecc extensions only if an ecc based ciphersuite is used. This improves compliance to RFC 4492, and as a result, solves interoperability issues with BouncyCastle. Raised by milenamil in #1157. + * Fix potential use-after-free in mbedtls_ssl_get_max_frag_len() + and mbedtls_ssl_get_record_expansion() after a session reset. Fixes #1941. Changes * Improve compatibility with some alternative CCM implementations by using diff --git a/library/ssl_tls.c b/library/ssl_tls.c index ca9b8c4325..716eabe250 100644 --- a/library/ssl_tls.c +++ b/library/ssl_tls.c @@ -5911,7 +5911,11 @@ static int ssl_session_reset_int( mbedtls_ssl_context *ssl, int partial ) ssl->transform_in = NULL; ssl->transform_out = NULL; + ssl->session_in = NULL; + ssl->session_out = NULL; + memset( ssl->out_buf, 0, MBEDTLS_SSL_BUFFER_LEN ); + if( partial == 0 ) memset( ssl->in_buf, 0, MBEDTLS_SSL_BUFFER_LEN ); @@ -6687,14 +6691,14 @@ int mbedtls_ssl_get_record_expansion( const mbedtls_ssl_context *ssl ) size_t transform_expansion; const mbedtls_ssl_transform *transform = ssl->transform_out; + if( transform == NULL ) + return( (int) mbedtls_ssl_hdr_len( ssl ) ); + #if defined(MBEDTLS_ZLIB_SUPPORT) if( ssl->session_out->compression != MBEDTLS_SSL_COMPRESS_NULL ) return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE ); #endif - if( transform == NULL ) - return( (int) mbedtls_ssl_hdr_len( ssl ) ); - switch( mbedtls_cipher_get_cipher_mode( &transform->cipher_ctx_enc ) ) { case MBEDTLS_MODE_GCM: