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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 2E376C47247 for ; Thu, 30 Apr 2020 13:55:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0450820873 for ; Thu, 30 Apr 2020 13:55:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588254935; bh=yHeiB67tW2XIZJMzXUe4enYchdDsqXbZcv1tiZPJtvc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=A1ohZqEdDqjBsa14+bkutBdmGhAMq3xWSGpa/hxklb1cUY3hJC0h1cd4nOC/LBLCe /r5KYLAKVkU0lm8MybOcIzIWqGKNQmnAG6VrCYkyVdMWmD7q9/8Tdvq99S/j9wRkOu jJ22eSkXfDKYw0IxIh05ckS6Wg6u9g0KJw3q1ftA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729183AbgD3Nze (ORCPT ); Thu, 30 Apr 2020 09:55:34 -0400 Received: from mail.kernel.org ([198.145.29.99]:37622 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729066AbgD3Nyv (ORCPT ); Thu, 30 Apr 2020 09:54:51 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D9D49208DB; Thu, 30 Apr 2020 13:54:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588254890; bh=yHeiB67tW2XIZJMzXUe4enYchdDsqXbZcv1tiZPJtvc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YjMknSh+jpAuzCIy3AxRN+iuhpZZPf1Ge9dcnhVsz8xP5pNQZy/s72LPwuQsucOB2 aw/KzLVETh/3KDTAoKBy4YIHAQ+CmJ1WXMP0vU2oiSRIwhcVnI61401/Se/MQn4dBK dD2ZdpjWmjFz1F4vR1mx+sZsKlYrOKOz5K44M8/s= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Taehee Yoo , "David S . Miller" , Sasha Levin , netdev@vger.kernel.org Subject: [PATCH AUTOSEL 4.9 15/17] macsec: avoid to set wrong mtu Date: Thu, 30 Apr 2020 09:54:31 -0400 Message-Id: <20200430135433.21204-15-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200430135433.21204-1-sashal@kernel.org> References: <20200430135433.21204-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore 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: Sasha Levin --- drivers/net/macsec.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/drivers/net/macsec.c b/drivers/net/macsec.c index da8bf327a3e98..df2ee65a33e35 100644 --- a/drivers/net/macsec.c +++ b/drivers/net/macsec.c @@ -3209,11 +3209,11 @@ static int macsec_newlink(struct net *net, struct net_device *dev, 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 *net, struct net_device *dev, 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) -- 2.20.1