In the Linux kernel, the following vulnerability has been resolved:
tcp: secure_seq: add back ports to TS offset
This reverts 28ee1b746f49 (secure_seq: downgrade to per-host timestamp offsets)
tcp_tw_recycle went away in 2017.
Zhouyan Deng reported off-path TCP source port leakage via SYN cookie side-channel that can be fixed in multiple ways.
One of them is to bring back TCP ports in TS offset randomization.
As a bonus, we perform a single siphash() computation to provide both an ISN and a TS offset.