: Bug in reading Ack Vectors

[CCID2]: Bug in reading Ack Vectors

In CCID2 the receiver-history is sorted in ascending order of sequence number, but the processing of received Ack Vectors requires the list traversal in the opposite direction.

The current code has a bug in this regard: the list traversal is upwards. As a consequence, only Ack Vectors with a run length of 1 will pass, in all other Ack Vectors the remaining (acked) sequence numbers are missed, and may later falsely be identified as lost.

Note: This bug is only visible when Ack Ratio > 1, since otherwise the run
lengths of Ack Vectors are 0.

---
 net/dccp/ccids/ccid2.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

@@ -666,7 +666,7 @@ static void ccid2_hc_tx_packet_recv(stru
 					done = 1;
 					break;
 				}
-				seqp = seqp->ccid2s_next;
+				seqp = seqp->ccid2s_prev;
 			}
 			if (done)
 				break;