From mboxrd@z Thu Jan 1 00:00:00 1970 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 97BA31DE8BF for ; Mon, 29 Dec 2025 13:04:03 +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=1767013443; cv=none; b=Ax8myNRvbrRQIcCPAezcIQ8vWMqXzWoqzJEEMXPN1IcjtQ7bqR5t4/RjeOWtDsHpU0c5vJ/zVguesK93e594jXagS69BE3qPH+1cbCOnBPxWbXvIOVNBPPo5MlgWkCcCJAwnxI3ruMF+kfjEn23BN438FAAahrPsjv/+M+fD6rw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767013443; c=relaxed/simple; bh=hvV9pWiWIxfroy0dR5AN1jvTbPO8VareSaOdV7zfNhI=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=docV7tqA49JCFmuReSAjgyV19+Oyz8setivm+W8CyktdpEy2C01ylg+yp9JF+yAguhaXPzTlMzeyHsp0bzHgEM/S1gmIAev+KfFbsmsqDtSmjbg/4y/MzQUgZ4fIo++Iddlv6+0PIT2WAIX3Kv55IgeE58s0WnXNECid+J+w9Qs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=gBDJkYjt; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="gBDJkYjt" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D41BBC4CEF7; Mon, 29 Dec 2025 13:04:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1767013443; bh=hvV9pWiWIxfroy0dR5AN1jvTbPO8VareSaOdV7zfNhI=; h=Subject:To:Cc:From:Date:From; b=gBDJkYjto65W6+/hQ7puwn21lJyEH3VRAiXbcXCxXSq0EP6pJNTqU7siGAc46XBKt Bx/WAdgrFukpPZ8pgyQI8WxBfc/gBMjatbV4XMd2TSxHQEA5vIaMmYeAzknBxMcXhB +IQQLHi5gUm2oGwAEICpQ4x/Wae9gP2FOVayfICw= Subject: FAILED: patch "[PATCH] mptcp: schedule rtx timer only after pushing data" failed to apply to 5.15-stable tree To: pabeni@redhat.com,kuba@kernel.org,matttbe@kernel.org Cc: From: Date: Mon, 29 Dec 2025 14:03:52 +0100 Message-ID: <2025122952-supervise-regulate-a26b@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 2ea6190f42d0416a4310e60a7fcb0b49fcbbd4fb # git commit -s git send-email --to '' --in-reply-to '2025122952-supervise-regulate-a26b@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 2ea6190f42d0416a4310e60a7fcb0b49fcbbd4fb Mon Sep 17 00:00:00 2001 From: Paolo Abeni Date: Fri, 5 Dec 2025 19:55:16 +0100 Subject: [PATCH] mptcp: schedule rtx timer only after pushing data The MPTCP protocol usually schedule the retransmission timer only when there is some chances for such retransmissions to happen. With a notable exception: __mptcp_push_pending() currently schedule such timer unconditionally, potentially leading to unnecessary rtx timer expiration. The issue is present since the blamed commit below but become easily reproducible after commit 27b0e701d387 ("mptcp: drop bogus optimization in __mptcp_check_push()") Fixes: 33d41c9cd74c ("mptcp: more accurate timeout") 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/20251205-net-mptcp-misc-fixes-6-19-rc1-v1-3-9e4781a6c1b8@kernel.org Signed-off-by: Jakub Kicinski diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index e212c1374bd0..d8a7f7029164 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -1623,7 +1623,7 @@ void __mptcp_push_pending(struct sock *sk, unsigned int flags) struct mptcp_sendmsg_info info = { .flags = flags, }; - bool do_check_data_fin = false; + bool copied = false; int push_count = 1; while (mptcp_send_head(sk) && (push_count > 0)) { @@ -1665,7 +1665,7 @@ void __mptcp_push_pending(struct sock *sk, unsigned int flags) push_count--; continue; } - do_check_data_fin = true; + copied = true; } } } @@ -1674,11 +1674,14 @@ void __mptcp_push_pending(struct sock *sk, unsigned int flags) if (ssk) mptcp_push_release(ssk, &info); - /* ensure the rtx timer is running */ - if (!mptcp_rtx_timer_pending(sk)) - mptcp_reset_rtx_timer(sk); - if (do_check_data_fin) + /* Avoid scheduling the rtx timer if no data has been pushed; the timer + * will be updated on positive acks by __mptcp_cleanup_una(). + */ + if (copied) { + if (!mptcp_rtx_timer_pending(sk)) + mptcp_reset_rtx_timer(sk); mptcp_check_send_data_fin(sk); + } } static void __mptcp_subflow_push_pending(struct sock *sk, struct sock *ssk, bool first)