Additionally initialize fd_set's via memset in mbedtls_net_poll
The initialization via FD_SET is not seen by memory sanitizers if
FD_SET is implemented through assembly. Additionally zeroizing the
respective fd_set's before calling FD_SET contents the sanitizers
and comes at a negligible computational overhead.
@@ -459,6 +459,12 @@ int mbedtls_net_poll( mbedtls_net_context *ctx, uint32_t rw, uint32_t timeout )
if( fd < 0 )
return( MBEDTLS_ERR_NET_INVALID_CONTEXT );
+ /* Ensure that memory sanitizers consider
+ * read_fds and write_fds as initialized even
+ * if FD_ZERO is implemented in assembly. */
+ memset( &read_fds, 0, sizeof( read_fds ) );
+ memset( &write_fds, 0, sizeof( write_fds ) );
+
FD_ZERO( &read_fds );
if( rw & MBEDTLS_NET_POLL_READ )
{
