commit 04685bc949e90a877656cf5020b6d4f90a9636a6
Author: Matt Caswell <matt@openssl.org>
Date:   Wed Jan 7 14:18:13 2015 +0000

    A memory leak can occur in dtls1_buffer_record if either of the calls to
    ssl3_setup_buffers or pqueue_insert fail. The former will fail if there is a
    malloc failure, whilst the latter will fail if attempting to add a duplicate
    record to the queue. This should never happen because duplicate records should
    be detected and dropped before any attempt to add them to the queue.
    Unfortunately records that arrive that are for the next epoch are not being
    recorded correctly, and therefore replays are not being detected.
    Additionally, these "should not happen" failures that can occur in
    dtls1_buffer_record are not being treated as fatal and therefore an attacker
    could exploit this by sending repeated replay records for the next epoch,
    eventually causing a DoS through memory exhaustion.
    
    Thanks to Chris Mueller for reporting this issue and providing initial
    analysis and a patch. Further analysis and the final patch was performed by
    Matt Caswell from the OpenSSL development team.
    
    CVE-2015-0206
    
    Reviewed-by: Dr Stephen Henson <steve@openssl.org>

diff --git a/ssl/d1_pkt.c b/ssl/d1_pkt.c
index 73ce488..0059fe2 100644
--- a/ssl/d1_pkt.c
+++ b/ssl/d1_pkt.c
@@ -212,7 +212,7 @@ dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority)
 	/* Limit the size of the queue to prevent DOS attacks */
 	if (pqueue_size(queue->q) >= 100)
 		return 0;
-		
+
 	rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));
 	item = pitem_new(priority, rdata);
 	if (rdata == NULL || item == NULL)
@@ -247,18 +247,22 @@ dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority)
 	if (!ssl3_setup_buffers(s))
 		{
 		SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
+		if (rdata->rbuf.buf != NULL)
+			OPENSSL_free(rdata->rbuf.buf);
 		OPENSSL_free(rdata);
 		pitem_free(item);
-		return(0);
+		return(-1);
 		}
 
 	/* insert should not fail, since duplicates are dropped */
 	if (pqueue_insert(queue->q, item) == NULL)
 		{
 		SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
+		if (rdata->rbuf.buf != NULL)
+			OPENSSL_free(rdata->rbuf.buf);
 		OPENSSL_free(rdata);
 		pitem_free(item);
-		return(0);
+		return(-1);
 		}
 
 	return(1);
@@ -314,8 +318,9 @@ dtls1_process_buffered_records(SSL *s)
             dtls1_get_unprocessed_record(s);
             if ( ! dtls1_process_record(s))
                 return(0);
-            dtls1_buffer_record(s, &(s->d1->processed_rcds), 
-                s->s3->rrec.seq_num);
+            if(dtls1_buffer_record(s, &(s->d1->processed_rcds),
+                s->s3->rrec.seq_num)<0)
+                return -1;
             }
         }
 
@@ -530,7 +535,6 @@ printf("\n");
 
 	/* we have pulled in a full packet so zero things */
 	s->packet_length=0;
-	dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */
 	return(1);
 
 f_err:
@@ -563,7 +567,8 @@ int dtls1_get_record(SSL *s)
 
 	/* The epoch may have changed.  If so, process all the
 	 * pending records.  This is a non-blocking operation. */
-	dtls1_process_buffered_records(s);
+	if(dtls1_process_buffered_records(s)<0)
+		return -1;
 
 	/* if we're renegotiating, then there may be buffered records */
 	if (dtls1_get_processed_record(s))
@@ -700,7 +705,9 @@ again:
 		{
 		if ((SSL_in_init(s) || s->in_handshake) && !s->d1->listen)
 			{
-			dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num);
+			if(dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num)<0)
+				return -1;
+			dtls1_record_bitmap_update(s, bitmap);/* Mark receipt of record. */
 			}
 		rr->length = 0;
 		s->packet_length = 0;
@@ -713,6 +720,7 @@ again:
 		s->packet_length = 0;  /* dump this record */
 		goto again;   /* get another record */
 		}
+	dtls1_record_bitmap_update(s, bitmap);/* Mark receipt of record. */
 
 	return(1);
 
@@ -864,7 +872,11 @@ start:
 		 * buffer the application data for later processing rather
 		 * than dropping the connection.
 		 */
-		dtls1_buffer_record(s, &(s->d1->buffered_app_data), rr->seq_num);
+		if(dtls1_buffer_record(s, &(s->d1->buffered_app_data), rr->seq_num)<0)
+			{
+			SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
+			return -1;
+			}
 		rr->length = 0;
 		goto start;
 		}
