In the Linux kernel, the following vulnerability has been resolved:

sctp: avoid livelock while updating retransmit path

sctp assoc update retran path() can loop forever when every remaining transport, including retran path, is SCTP UNCONFIRMED: the state check runs before the wraparound test, so the loop cannot observe that it has completed a full pass.

Fix this by considering a transport only when it is not UNCONFIRMED, then checking whether the walk has returned to retran path. This makes the full-pass termination independent of the transport state while preserving the existing fallback selection semantics.

Also restore the NULL guard around the retran path assignment. In the all-UNCONFIRMED case there is no eligible replacement transport, and installing NULL would leave later retransmit-path users and the debug print with a NULL path.