[$] The TCP SACK panic

Selectiveacknowledgment (SACK) is a technique used by TCP to help alleviatecongestion that can arise due to the retransmission of dropped packets. It allowsthe endpoints to describe which pieces of the data they have received,so that only the missing pieces need to be retransmitted. However, a bugwas recently found in the Linux implementation of SACK that allows remoteattackers to panic the system by sending crafted SACK information.