From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 6B09F34EEE3; Sun, 7 Jun 2026 11:00:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780830019; cv=none; b=b2FupyPkrPaikHsndcWAZTdM+k8UCxYPzsG3RgOTmOSU8MMURHPXC+eS9KSLdCmlVFpa/uAhnKwRFcTtxqsPEZaWIM23E6LyGE/hNrvhAiMNAp1nV+lpbH41IzjTrj/L8jtoswoUTFzBraGph07veOfIswItojHnOmLopyXRqto= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780830019; c=relaxed/simple; bh=tRe8vpODr1qNtQeI/wez7MMx9p9YWb1L3iMALTN2rvE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=PVfoh/W84oTiWnVmVk2vnSoEQsH82iNIFVNEwu61v9FX3R9JCKmK8GOZ4fIdfNgE1G+MCMWYXpOXj8kUt+ebjxtpCOdSdfJK0+fqOSZyWO7iyYScEfAllihcicfizFocpChZtrwj3xhbGq7p2NveqsPcgwOc1t6Q1K9pU1SsaB8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=nVkymqSp; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="nVkymqSp" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 27C3E1F00893; Sun, 7 Jun 2026 11:00:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1780830011; bh=yk4WvtpvvsN2e/hQLVFOb2lBt7bxs8HSp3UsLEMAVhw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=nVkymqSpshffJ0PJIloTuftAGtW4VdhiIoJq0COrHceGeVPo8t+7J+ZNulYJWwjjo N4OgNvaWUOku4y3DaDiwVdXLHpKivcA8PURrDwVjHStbMklCl8oZKrBBgkPK+8Q23P 5OP4F/izO5vVKmt3R42nYcvdcEISg7TJ7np+n4UU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Paolo Abeni , "Matthieu Baerts (NGI0)" , Sasha Levin Subject: [PATCH 6.18 299/315] mptcp: reset rcv wnd on disconnect Date: Sun, 7 Jun 2026 12:01:26 +0200 Message-ID: <20260607095738.577909940@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260607095727.528828913@linuxfoundation.org> References: <20260607095727.528828913@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Paolo Abeni [ Upstream commit 0981f90e1a05773a4c29c6e720f5ea1e3c8f1876 ] If the MPTCP socket fallback to TCP before the MP handshake completion, the IASN remain 0, and the rcv_wnd_sent field is not explicitly initialized, just incremented over time with the data transfer. At disconnect time such value is not cleared. If the next connection falls back to TCP before the MP handshake completion, the data transfer will keep incrementing the receive window end sequence starting from the last value used in the previous connection: the announced window will be unrelated from the actual receiver buffer size and likely too big. Address the issue zeroing the field at disconnect time. Fixes: b29fcfb54cd7 ("mptcp: full disconnect implementation") 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/20260515-net-mptcp-misc-fixes-7-1-rc4-v2-4-701e96419f2f@kernel.org Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- net/mptcp/protocol.c | 1 + 1 file changed, 1 insertion(+) --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -3335,6 +3335,7 @@ static int mptcp_disconnect(struct sock /* for fallback's sake */ WRITE_ONCE(msk->ack_seq, 0); + atomic64_set(&msk->rcv_wnd_sent, 0); WRITE_ONCE(sk->sk_shutdown, 0); sk_error_report(sk);