Commit 58c27c20 authored by Matt Caswell's avatar Matt Caswell
Browse files

Fix crash as a result of MULTIBLOCK 



The MULTIBLOCK code uses a "jumbo" sized write buffer which it allocates
and then frees later. Pipelining however introduced multiple pipelines. It
keeps track of how many pipelines are initialised using numwpipes.
Unfortunately the MULTIBLOCK code was not updating this when in deallocated
its buffers, leading to a buffer being marked as initialised but set to
NULL.

RT#4618

Reviewed-by: default avatarRich Salz <rsalz@openssl.org>
parent 0fae8150

ssl/record/rec_layer_s3.c

+12 −14
Original line number Diff line number Diff line
@@ -423,23 +423,21 @@ int ssl3_write_bytes(SSL *s, int type, const void *buf_, int len) 
            else

                packlen *= 4;



            wb->buf = OPENSSL_malloc(packlen);

            if (wb->buf == NULL) {

            if (!ssl3_setup_write_buffer(s, 1, packlen)) {

                SSLerr(SSL_F_SSL3_WRITE_BYTES, ERR_R_MALLOC_FAILURE);

                return -1;

            }

            wb->len = packlen;

        } else if (tot == len) { /* done? */

            OPENSSL_free(wb->buf); /* free jumbo buffer */

            wb->buf = NULL;

            /* free jumbo buffer */

            ssl3_release_write_buffer(s);

            return tot;

        }



        n = (len - tot);

        for (;;) {

            if (n < 4 * max_send_fragment) {

                OPENSSL_free(wb->buf); /* free jumbo buffer */

                wb->buf = NULL;

                /* free jumbo buffer */

                ssl3_release_write_buffer(s);

                break;

            }
@@ -471,8 +469,8 @@ int ssl3_write_bytes(SSL *s, int type, const void *buf_, int len) 
                                          sizeof(mb_param), &mb_param);



            if (packlen <= 0 || packlen > (int)wb->len) { /* never happens */

                OPENSSL_free(wb->buf); /* free jumbo buffer */

                wb->buf = NULL;

                /* free jumbo buffer */

                ssl3_release_write_buffer(s);

                break;

            }
@@ -502,15 +500,15 @@ int ssl3_write_bytes(SSL *s, int type, const void *buf_, int len) 
            i = ssl3_write_pending(s, type, &buf[tot], nw);

            if (i <= 0) {

                if (i < 0 && (!s->wbio || !BIO_should_retry(s->wbio))) {

                    OPENSSL_free(wb->buf);

                    wb->buf = NULL;

                    /* free jumbo buffer */

                    ssl3_release_write_buffer(s);

                }

                s->rlayer.wnum = tot;

                return i;

            }

            if (i == (int)n) {

                OPENSSL_free(wb->buf); /* free jumbo buffer */

                wb->buf = NULL;

                /* free jumbo buffer */

                ssl3_release_write_buffer(s);

                return tot + i;

            }

            n -= i;
@@ -650,7 +648,7 @@ int do_ssl3_write(SSL *s, int type, const unsigned char *buf, 
    }



    if (s->rlayer.numwpipes < numpipes)

        if (!ssl3_setup_write_buffer(s, numpipes))

        if (!ssl3_setup_write_buffer(s, numpipes, 0))

            return -1;



    if (totlen == 0 && !create_empty_fragment)

ssl/record/record_locl.h

+1 −1
Original line number Diff line number Diff line
@@ -69,7 +69,7 @@ void SSL3_BUFFER_clear(SSL3_BUFFER *b); 
void SSL3_BUFFER_set_data(SSL3_BUFFER *b, const unsigned char *d, int n);

void SSL3_BUFFER_release(SSL3_BUFFER *b);

__owur int ssl3_setup_read_buffer(SSL *s);

__owur int ssl3_setup_write_buffer(SSL *s, unsigned int numwpipes);

__owur int ssl3_setup_write_buffer(SSL *s, unsigned int numwpipes, size_t len);

int ssl3_release_read_buffer(SSL *s);

int ssl3_release_write_buffer(SSL *s);

ssl/record/ssl3_buffer.c

+16 −15
Original line number Diff line number Diff line
@@ -74,16 +74,16 @@ int ssl3_setup_read_buffer(SSL *s) 
    return 0;

}



int ssl3_setup_write_buffer(SSL *s, unsigned int numwpipes)

int ssl3_setup_write_buffer(SSL *s, unsigned int numwpipes, size_t len)

{

    unsigned char *p;

    size_t len, align = 0, headerlen;

    size_t align = 0, headerlen;

    SSL3_BUFFER *wb;

    unsigned int currpipe;



    s->rlayer.numwpipes = numwpipes;





    if (len == 0) {

        if (SSL_IS_DTLS(s))

            headerlen = DTLS1_RT_HEADER_LENGTH + 1;

        else
@@ -101,6 +101,7 @@ int ssl3_setup_write_buffer(SSL *s, unsigned int numwpipes) 
#endif

        if (!(s->options & SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS))

            len += headerlen + align + SSL3_RT_SEND_MAX_ENCRYPTED_OVERHEAD;

    }



    wb = RECORD_LAYER_get_wbuf(&s->rlayer);

    for (currpipe = 0; currpipe < numwpipes; currpipe++) {
@@ -125,7 +126,7 @@ int ssl3_setup_buffers(SSL *s) 
{

    if (!ssl3_setup_read_buffer(s))

        return 0;

    if (!ssl3_setup_write_buffer(s, 1))

    if (!ssl3_setup_write_buffer(s, 1, 0))

        return 0;

    return 1;

}