Commit a925e7db authored by Matt Caswell's avatar Matt Caswell
Browse files

Don't memcpy the contents of an empty fragment 



In DTLS if we have buffered a fragment for a zero length message (e.g.
ServerHelloDone) then, when we unbuffered the fragment, we were attempting
to memcpy the contents of the fragment which is zero length and a NULL
pointer. This is undefined behaviour. We should check first whether we
have a zero length fragment.

Fixes a travis issue.

[extended tests]

Reviewed-by: default avatarRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/6223)
parent c82c3462

ssl/statem/statem_dtls.c

+1 −1
Original line number Diff line number Diff line
@@ -504,7 +504,7 @@ static int dtls1_retrieve_buffered_fragment(SSL *s, size_t *len) 
        /* Calls SSLfatal() as required */

        ret = dtls1_preprocess_fragment(s, &frag->msg_header);



        if (ret) {

        if (ret && frag->msg_header.frag_len > 0) {

            unsigned char *p =

                (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH;

            memcpy(&p[frag->msg_header.frag_off], frag->fragment,