From 7f501faddb3c064606fa9bfc36193df30a80bb0b Mon Sep 17 00:00:00 2001 From: "Matthieu Baerts (NGI0)" Date: Fri, 12 Sep 2025 14:52:23 +0200 Subject: mptcp: tfo: record 'deny join id0' info [ Upstream commit 92da495cb65719583aa06bc946aeb18a10e1e6e2 ] When TFO is used, the check to see if the 'C' flag (deny join id0) was set was bypassed. This flag can be set when TFO is used, so the check should also be done when TFO is used. Note that the set_fully_established label is also used when a 4th ACK is received. In this case, deny_join_id0 will not be set. Fixes: dfc8d0603033 ("mptcp: implement delayed seq generation for passive fastopen") Reviewed-by: Mat Martineau Signed-off-by: Matthieu Baerts (NGI0) Link: https://patch.msgid.link/20250912-net-mptcp-pm-uspace-deny_join_id0-v1-4-40171884ade8@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/mptcp/options.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'net') diff --git a/net/mptcp/options.c b/net/mptcp/options.c index c6983471dca5..bb4253aa675a 100644 --- a/net/mptcp/options.c +++ b/net/mptcp/options.c @@ -984,13 +984,13 @@ static bool check_fully_established(struct mptcp_sock *msk, struct sock *ssk, return false; } - if (mp_opt->deny_join_id0) - WRITE_ONCE(msk->pm.remote_deny_join_id0, true); - if (unlikely(!READ_ONCE(msk->pm.server_side))) pr_warn_once("bogus mpc option on established client sk"); set_fully_established: + if (mp_opt->deny_join_id0) + WRITE_ONCE(msk->pm.remote_deny_join_id0, true); + mptcp_data_lock((struct sock *)msk); __mptcp_subflow_fully_established(msk, subflow, mp_opt); mptcp_data_unlock((struct sock *)msk); -- cgit v1.2.3