CyberRota Analysis
AI-GeneratedThe vulnerability affects the Linux kernel's implementation of MultiPath TCP (MPTCP) Fast Open, where passive TCP Fast Open can incorrectly accept SYN packets without data, leading to potential stale state issues in MPTCP subflows. This flaw could result in state confusion during the establishment of connections, which may compromise the integrity of data transmission. Organizations utilizing Linux-based systems with MPTCP should prioritize addressing this vulnerability to mitigate potential disruptions in network communications.
Original NVD Description
In the Linux kernel, the following vulnerability has been resolved: mptcp: fastopen: only mark MPTFO subflows with SYN data Passive TCP Fast Open accepts a valid-cookie SYN even when it carries no data. In that case the child socket's receive queue is intentionally left empty. mptcp_fastopen_subflow_synack_set_params() set is_mptfo before checking for queued SYN data. That made data-less TFO SYNs hit a WARN and, if the warning was non-fatal, left stale MPTFO state behind. The stale flag could later trigger a state-confusion bug in check_fully_established(). Only mark the subflow as MPTFO after confirming that an SKB was queued. Return quietly when the receive queue is empty. Note that mptcp_subflow_context's is_mptfo field is now not just about subflows where the TFO was present, but about MPTFO subflow that consumed SYN data. Only having a valid cookie but not carrying data is not really "doing TFO".