From 56b824eb49d6258aa0bad09a406ceac3f643cdae Mon Sep 17 00:00:00 2001 From: Paolo Abeni Date: Mon, 30 Dec 2024 19:12:32 +0100 Subject: mptcp: prevent excessive coalescing on receive Currently the skb size after coalescing is only limited by the skb layout (the skb must not carry frag_list). A single coalesced skb covering several MSS can potentially fill completely the receive buffer. In such a case, the snd win will zero until the receive buffer will be empty again, affecting tput badly. Fixes: 8268ed4c9d19 ("mptcp: introduce and use mptcp_try_coalesce()") Cc: stable@vger.kernel.org # please delay 2 weeks after 6.13-final release Signed-off-by: Paolo Abeni Reviewed-by: Mat Martineau Signed-off-by: Matthieu Baerts (NGI0) Link: https://patch.msgid.link/20241230-net-mptcp-rbuf-fixes-v1-3-8608af434ceb@kernel.org Signed-off-by: Jakub Kicinski --- net/mptcp/protocol.c | 1 + 1 file changed, 1 insertion(+) (limited to 'net') diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 5307fff9d995..1b2e7cbb577f 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -136,6 +136,7 @@ static bool mptcp_try_coalesce(struct sock *sk, struct sk_buff *to, int delta; if (MPTCP_SKB_CB(from)->offset || + ((to->len + from->len) > (sk->sk_rcvbuf >> 3)) || !skb_try_coalesce(to, from, &fragstolen, &delta)) return false; -- cgit v1.2.3