6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet <edumazet@xxxxxxxxxx> [ Upstream commit c1665273bdc7c201766c65e561c06711f2e050dc ] mp_opt->hmac contains uninitialized data unless OPTION_MPTCP_MPJ_ACK was set in mptcp_parse_option(). We must refine the condition before we call subflow_hmac_valid(). Fixes: f296234c98a8 ("mptcp: Add handling of incoming MP_JOIN requests") Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx> Cc: Florian Westphal <fw@xxxxxxxxx> Cc: Peter Krystad <peter.krystad@xxxxxxxxxxxxxxx> Cc: Matthieu Baerts <matttbe@xxxxxxxxxx> Cc: Mat Martineau <martineau@xxxxxxxxxx> Cc: Geliang Tang <geliang.tang@xxxxxxxxx> Reviewed-by: Simon Horman <horms@xxxxxxxxxx> Acked-by: Paolo Abeni <pabeni@xxxxxxxxxx> Reviewed-by: Mat Martineau <martineau@xxxxxxxxxx> Link: https://lore.kernel.org/r/20240111194917.4044654-3-edumazet@xxxxxxxxxx Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- net/mptcp/subflow.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index 45b8115b363b..d6ee0e52ea41 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -788,7 +788,7 @@ static struct sock *subflow_syn_recv_sock(const struct sock *sk, } else if (subflow_req->mp_join) { mptcp_get_options(skb, &mp_opt); - if (!(mp_opt.suboptions & OPTIONS_MPTCP_MPJ) || + if (!(mp_opt.suboptions & OPTION_MPTCP_MPJ_ACK) || !subflow_hmac_valid(req, &mp_opt) || !mptcp_can_accept_new_subflow(subflow_req->msk)) { SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINACKMAC); -- 2.43.0