mptcp_setsockopt_all_sf() was missing a call to sockopt_seq_inc(). This is required not to cause missing synchronization for newer subflows created later on. This helper is called each time a socket option is set on subflows, and future ones will need to inherit this option after their creation. Fixes: 51c5fd09e1b4 ("mptcp: add TCP_MAXSEG sockopt support") Cc: stable@vger.kernel.org Suggested-by: Paolo Abeni Reviewed-by: Mat Martineau Signed-off-by: Matthieu Baerts (NGI0) --- net/mptcp/sockopt.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c index 0efe40be2fde..1cf608e7357b 100644 --- a/net/mptcp/sockopt.c +++ b/net/mptcp/sockopt.c @@ -812,6 +812,10 @@ static int mptcp_setsockopt_all_sf(struct mptcp_sock *msk, int level, if (ret) break; } + + if (!ret) + sockopt_seq_inc(msk); + return ret; } -- 2.53.0