From: Paolo Abeni Date: Fri, 1 May 2026 19:35:36 +0000 (+0200) Subject: mptcp: fix rx timestamp corruption on fastopen X-Git-Tag: v7.1-rc3~26^2~41^2~1 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6254a16d6f0c672e3809ca5d7c9a28a55d71f764;p=thirdparty%2Fkernel%2Flinux.git mptcp: fix rx timestamp corruption on fastopen The skb cb offset containing the timestamp presence flag is cleared before loading such information. Cache such value before MPTCP CB initialization. Fixes: 36b122baf6a8 ("mptcp: add subflow_v(4,6)_send_synack()") Cc: stable@vger.kernel.org Signed-off-by: Paolo Abeni Reviewed-by: Matthieu Baerts (NGI0) Signed-off-by: Matthieu Baerts (NGI0) Link: https://patch.msgid.link/20260501-net-mptcp-misc-fixes-7-1-rc3-v1-3-b70118df778e@kernel.org Signed-off-by: Jakub Kicinski --- diff --git a/net/mptcp/fastopen.c b/net/mptcp/fastopen.c index 82ec15bcfd7f..082c46c0f50e 100644 --- a/net/mptcp/fastopen.c +++ b/net/mptcp/fastopen.c @@ -12,6 +12,7 @@ void mptcp_fastopen_subflow_synack_set_params(struct mptcp_subflow_context *subf struct sock *sk, *ssk; struct sk_buff *skb; struct tcp_sock *tp; + bool has_rxtstamp; /* on early fallback the subflow context is deleted by * subflow_syn_recv_sock() @@ -40,12 +41,13 @@ void mptcp_fastopen_subflow_synack_set_params(struct mptcp_subflow_context *subf */ tp->copied_seq += skb->len; subflow->ssn_offset += skb->len; + has_rxtstamp = TCP_SKB_CB(skb)->has_rxtstamp; /* Only the sequence delta is relevant */ MPTCP_SKB_CB(skb)->map_seq = -skb->len; MPTCP_SKB_CB(skb)->end_seq = 0; MPTCP_SKB_CB(skb)->offset = 0; - MPTCP_SKB_CB(skb)->has_rxtstamp = TCP_SKB_CB(skb)->has_rxtstamp; + MPTCP_SKB_CB(skb)->has_rxtstamp = has_rxtstamp; MPTCP_SKB_CB(skb)->cant_coalesce = 1; mptcp_data_lock(sk);