From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6D98EC4724C for ; Fri, 1 May 2020 13:59:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4E563206D9 for ; Fri, 1 May 2020 13:59:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588341583; bh=oKniy+kiYwiUS+eRELPq61cbjj8BQLGPrq2i4CNt50w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=yt2MW1gdEVUKYX6eZt29/Bw4t6r+HVPpV7fEkXNxBhcx5MtHlXUkE+KQzsY8n46Uo rjCgkrHI3p7Ld7HKu9Qx7jehARtR7quCIKYzetdm0tX5y/kmZWunbTpqUcSy59ygDb qeV2wZP+6GwMJLi/ndKuum2GxIUVV7MY4MIk1suk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729650AbgEAN2i (ORCPT ); Fri, 1 May 2020 09:28:38 -0400 Received: from mail.kernel.org ([198.145.29.99]:51674 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729626AbgEAN2c (ORCPT ); Fri, 1 May 2020 09:28:32 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3A33D2166E; Fri, 1 May 2020 13:28:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588339711; bh=oKniy+kiYwiUS+eRELPq61cbjj8BQLGPrq2i4CNt50w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=2sl4Oig9lxyJciylx9oOnTpeoxkobz6KUGbQNv0y/zCYu70KOrPvZupSqz5sUy7bE wyHvvef/BZpaPFpSl8TOm3tQnaVXKjLcgjjt4SLC+gAoRAcpscHDrFNGlVhXu9+wf1 7I3Y4gNp3w+beX5GUvwTgx5CPQ6j2brqc5U5mgFc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Taehee Yoo , "David S. Miller" Subject: [PATCH 4.9 21/80] macsec: avoid to set wrong mtu Date: Fri, 1 May 2020 15:21:15 +0200 Message-Id: <20200501131521.178970534@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200501131513.810761598@linuxfoundation.org> References: <20200501131513.810761598@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Taehee Yoo [ Upstream commit 7f327080364abccf923fa5a5b24e038eb0ba1407 ] When a macsec interface is created, the mtu is calculated with the lower interface's mtu value. If the mtu of lower interface is lower than the length, which is needed by macsec interface, macsec's mtu value will be overflowed. So, if the lower interface's mtu is too low, macsec interface's mtu should be set to 0. Test commands: ip link add dummy0 mtu 10 type dummy ip link add macsec0 link dummy0 type macsec ip link show macsec0 Before: 11: macsec0@dummy0: mtu 4294967274 After: 11: macsec0@dummy0: mtu 0 Fixes: c09440f7dcb3 ("macsec: introduce IEEE 802.1AE driver") Signed-off-by: Taehee Yoo Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/macsec.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) --- a/drivers/net/macsec.c +++ b/drivers/net/macsec.c @@ -3209,11 +3209,11 @@ static int macsec_newlink(struct net *ne struct nlattr *tb[], struct nlattr *data[]) { struct macsec_dev *macsec = macsec_priv(dev); + rx_handler_func_t *rx_handler; + u8 icv_len = DEFAULT_ICV_LEN; struct net_device *real_dev; - int err; + int err, mtu; sci_t sci; - u8 icv_len = DEFAULT_ICV_LEN; - rx_handler_func_t *rx_handler; if (!tb[IFLA_LINK]) return -EINVAL; @@ -3229,7 +3229,11 @@ static int macsec_newlink(struct net *ne if (data && data[IFLA_MACSEC_ICV_LEN]) icv_len = nla_get_u8(data[IFLA_MACSEC_ICV_LEN]); - dev->mtu = real_dev->mtu - icv_len - macsec_extra_len(true); + mtu = real_dev->mtu - icv_len - macsec_extra_len(true); + if (mtu < 0) + dev->mtu = 0; + else + dev->mtu = mtu; rx_handler = rtnl_dereference(real_dev->rx_handler); if (rx_handler && rx_handler != macsec_handle_frame)