From patchwork Sun Feb 9 17:55:05 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthieu Baerts X-Patchwork-Id: 13967029 X-Patchwork-Delegate: matthieu.baerts@tessares.net Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C6EFB1D934D; Sun, 9 Feb 2025 17:55:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739123712; cv=none; b=adzsAelz8uAZxMqN1zpE0wyWbSTurctq+74R7a4WlWjNKq6j7qO9QKESzv/Ycn3CzxK7gNLgc82PDh5p/GLgzDS1MYpWT3RMsUT9cueJKX7Zl0/YkxhJtdxN6PdgzvNNDNoGKJ7X2EZNrAzfkOeXxUQtSAdgr3vLX01iQFw+gKs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739123712; c=relaxed/simple; bh=VKkgpE1ckVxffCK3SGKfm31z78bRnpKGHB1DNkAE+pk=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=RlVeDVwBB5ZfTgAsQp3uM+XGRsmzMuCgryLHAtWjzZ622txITdrgVf0HRkrnXS9eUq7tQBF+MpaYNannD+NGFOpmD6t2pdsygFoP4WP+LAYkvXA7fuKbcjZ8KseM4ylhwaBADdn3B8jpR1yDdFHV60nsnOYQDYR9OqPnaWcRNQE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=fhK3oAt9; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="fhK3oAt9" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7C53CC4CEDD; Sun, 9 Feb 2025 17:55:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1739123712; bh=VKkgpE1ckVxffCK3SGKfm31z78bRnpKGHB1DNkAE+pk=; h=From:To:Cc:Subject:Date:From; b=fhK3oAt9Mib6cHmTtYIdRqgE5ZYbitVItF62mSEGnQ+nAiROwxcVe9iduIv/wik8i 5Ah97mu9A1bjAUtEchomzSLs1bYbSvdoXFmBFMO6Lu68KXEz64tSDIwVONtJYvrPCr +5gtN+f2pg/HdawUk0ssFzjwtf7JqsRwlZv0iDXV+D6C9OpYApNfAjPNk86MoJkGWN 33mhgLydor1thmzRJkj/dN1tUO3Llf6RqVJVTf8Rr/8bqWRWLIMQYybqhrJgpj7iHT 2tqZLApLkZdBDtrxuEe4ekhAkiDrOpMaQExIs8WN6ugc8BxUZGQPi+0d27Fq6jqBSR L6XWNeTDscY+w== From: "Matthieu Baerts (NGI0)" To: stable@vger.kernel.org, gregkh@linuxfoundation.org Cc: sashal@kernel.org, MPTCP Upstream , Paolo Abeni , Mat Martineau , "Matthieu Baerts (NGI0)" , Jakub Kicinski Subject: [PATCH 5.15.y] mptcp: prevent excessive coalescing on receive Date: Sun, 9 Feb 2025 18:55:05 +0100 Message-ID: <20250209175504.3405385-2-matttbe@kernel.org> X-Mailer: git-send-email 2.47.1 Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=1472; i=matttbe@kernel.org; h=from:subject; bh=8cp6QKlSyOtDX6v4zGEeoGyzl3mMEuUDCopn5jMee0I=; b=owEBbQKS/ZANAwAIAfa3gk9CaaBzAcsmYgBnqOv4770LDGdBZB399WVMHnfl1+nHJrnLlev6q JjE5NUO59SJAjMEAAEIAB0WIQToy4X3aHcFem4n93r2t4JPQmmgcwUCZ6jr+AAKCRD2t4JPQmmg c8QeD/9ZSsoYB5z0LRs7FoYiToQV9ziNKsDkK9QU5ZLCHubv3HlL3f01/wuQYWQuPFQ0PS0wc/1 414UWhsbFWyk1MyqEBWPA3DV5fsx/VGZNiRfA1JxiRynfVL/S3XbJpYOuACTIozzk442h5/Et9s Hc/w0NVt63oRb6nUxjY3Ux5D/FDFVPHjlFe05GxLHpehvsKx5/X0S0JJwzQ4j/hm8wqQB9kfxsN QT+cVf14wswBcFA8kqCqFlPOJW5U4KawejMta6o7Bdp7Y3tlipEr4m1EiScdEhlz2HuZM0gat+K cI3aWEsGyVbYxGY6bpo7Z11SMOqgB0gBmGJT5n6lpigCt+COvbLHe+IWpkckxDjkIFNGdVLWN9X 81tyvmEvQMamY37HHC8ZcFmechcxkLALBi2/e2SXlrT9p6RouvwHsp7O3YNW80vyyWucNjIHml6 TWoSoJhwd52wwBZGg2aA4Sqy1aqTEt2Vgl6xEGXPhc3E3eyDGz8H8BAIGC7e9IRzCzSztRpEPnd TD3Y6RAoqHiqYSGGBBE2j3mCTqglfTcX5aN4t4Q/lczmMpEEzUpzIPasrENFQsHXtmHS1G7vzXB Od8BrFaaSQBFt+6objsg6+M3dLHXLZ84ULw+EaKBMqBdfyHkZeGqeDoVyWMTvVh8mgenbUsvLVa jNCo97P0VWU3v3A== X-Developer-Key: i=matttbe@kernel.org; a=openpgp; fpr=E8CB85F76877057A6E27F77AF6B7824F4269A073 From: Paolo Abeni commit 56b824eb49d6258aa0bad09a406ceac3f643cdae upstream. 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 Signed-off-by: Matthieu Baerts (NGI0) --- Notes: - We asked to delay the patch. There were no conflicts. --- net/mptcp/protocol.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index f337dd3323a0..c6a11d6df516 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -133,6 +133,7 @@ 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;