From patchwork Sun Feb 9 17:48:31 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthieu Baerts X-Patchwork-Id: 13967027 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 139531F95E; Sun, 9 Feb 2025 17:48:37 +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=1739123318; cv=none; b=Z9dZqDStsZlCSQXxZjHjieVd5M2yIl7is2B5FUKOoV3nZovIswFkSQt4YQyULEr/fqkC/O/SkC7/MZ28KiTJwcj4fcYtyIy1R3PBRKenUETAWM3RndRprHcHnBWil8yhZKLKIcsU4KvGlX5Z5r8Cdiv1178tjsC26Ki18LuWecY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739123318; c=relaxed/simple; bh=fzDuiRpRL2d1xWH0J2p66ofVjRH7WKy0ma5rO/VFPHU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=lrWia8NYrCpnTJMPTkoCxiKlskKIlwhpP5yDk8820sh2/EyBar1VoMT+4yuGbRcc2XLNAiCkczPWMUqVAp1fY4GP3ud6rCk8MoWgncWoMf15YfMM89OrDixsNYO56UcLagDQ4szIRwkxGRqK1uUCvq0uVi2UBpEsToiXVVMT8+s= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=DhElYdiN; 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="DhElYdiN" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EE69FC4CEDD; Sun, 9 Feb 2025 17:48:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1739123317; bh=fzDuiRpRL2d1xWH0J2p66ofVjRH7WKy0ma5rO/VFPHU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DhElYdiNwV4D2BZZ4LHw8lXQ4yG1ENhvH5MVcA4MiDDH2Z/zhaV3tAzWQ3Nu4YF8g oiXVvSQcOH7N802Wc7P4tXSpzFDgAAIsdgZXhg2ntIU4gRhyCNXz3aAG0Y3rgaSkwx RfR83qUH1CTHzKmpZfONuf9VjIAgSUHMTZutatHG3q0vgDSNjFm84lDSppSgnknJgR 9z4SAAofhSgL3IY/FzAbvv3VvknDMlTEIyvWY4+pVT68oRWWKoBw0ag/Kkm/yexp+V cCyxvOr1YAh2MqLsOzzj4CDV44VrY+Gg4pKD1MwlAq27p74Yyk7RcEDm+37+RBP8ez +swQOk8JSgVqA== From: "Matthieu Baerts (NGI0)" To: mptcp@lists.linux.dev, stable@vger.kernel.org, gregkh@linuxfoundation.org Cc: Paolo Abeni , Mat Martineau , "Matthieu Baerts (NGI0)" , Jakub Kicinski Subject: [PATCH 6.1.y 2/2] mptcp: prevent excessive coalescing on receive Date: Sun, 9 Feb 2025 18:48:31 +0100 Message-ID: <20250209174828.3397229-6-matttbe@kernel.org> X-Mailer: git-send-email 2.47.1 In-Reply-To: <2025020435-eagle-precision-e8dd@gregkh> References: <2025020435-eagle-precision-e8dd@gregkh> 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=1401; i=matttbe@kernel.org; h=from:subject; bh=eFLGENSx3/TjLkm7K8v/Dyj0E/Q5+QNivasGS2+NndA=; b=owEBbQKS/ZANAwAIAfa3gk9CaaBzAcsmYgBnqOps5XQb5RaSqvj+b1SvCFhSRw0TTR6gtrOfZ +L/qxCC796JAjMEAAEIAB0WIQToy4X3aHcFem4n93r2t4JPQmmgcwUCZ6jqbAAKCRD2t4JPQmmg c+vzEADwx3xmPjUOIq0XA62zt1wFRXt5e1tH5gqu5//7xNYTuVx7CEGjaNn16CFREzkCO+Jh6GP 7tS3Vz152D01WmrePJFt/1boMrykSgDB2+UfywDL2Y6ioVy2gOpQuotA9itzvqmkBuiEHwciVI7 b87SF1S3KHUmf0NIrEZEZTbhvL+0ec3Ih9t5UOwYMgeAdBqBh4ZZF1GAiuKknDcraQ6PK1VREuq 7WdCFclm21QpFKaeegH1HssLuazQ4MAUWRqCxXkmhRQJWpFloLDbttXWvZdbaBlnl1e81ZjGu8Q tkcJ48LWou77vPcbP+snCH2R/4OHpby39qI77zIUuyG/UD0GxwlLS3frqErbssYiNaKuEAdmodp kELYDDmpLZxsJyx7rzS0YqX7ZNlv2OO1Vucy/UdETTpHKNVnDQ4bHQb6guR5tbBBgBGoau8BUyB 7BWAePP5Qv7paBWlX4AqyPNyUnFxicn+yOMuSxHZhYrjfqJWlbH/rg6EPKM2E0nUHLBsDR8AnSr b8y6uEokxJMQrTk3ewro0M1lvkZv0CVnKGibKEgJ9GAgLdDff46B5nHYDKp0nQKNaKkUFntkgmt 6a8P6Ydx2h8E+eg9FG2vb0XXpCX+TbMXSeRDc3vBaIBwMeGz0C2OLQhN7wuSre5AoWpPB+Mdupc NmH6o2zKlNfXk2A== 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) --- net/mptcp/protocol.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 0848e63bac65..82eaf20268e4 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -149,6 +149,7 @@ 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;