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=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 D192BC83004 for ; Tue, 28 Apr 2020 18:38:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AB01820575 for ; Tue, 28 Apr 2020 18:38:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588099135; bh=YqMhhaim/jzNbsVKd4Bfn1CEZ7m28Z+4VfMAyZgXLZ8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=bX/K0eLVlxC07oYRV37Yj6YEfBzzApiMozs5dte30zsTmgNTtZ71ep1rOitp04rPn CBuoBS8WHlFEEBllN7NijdgnTFphJgz7nB/Q8j2Fgn9x9WZAji7v6hw1eaeGWbU5GX svohvFLksjQM7hTlM2R5w9a3fWiBsBM+kthMNaBg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728965AbgD1Siy (ORCPT ); Tue, 28 Apr 2020 14:38:54 -0400 Received: from mail.kernel.org ([198.145.29.99]:57500 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730681AbgD1Siv (ORCPT ); Tue, 28 Apr 2020 14:38:51 -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 E827B208E0; Tue, 28 Apr 2020 18:38:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588099131; bh=YqMhhaim/jzNbsVKd4Bfn1CEZ7m28Z+4VfMAyZgXLZ8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DA0ScyKcG8GZcsWu57rC4dUR4QLhUWfSOdlHGVldn1FhR7L967VeiQ4lJRan7Llvo 6AtRc1iKjJMu2gxwIcq2bH5NmC9NljtR6VmxV6UKndCPr2x3FtAgWkVywmJfyM+8Aw xGsrStFFLxfcD/p9pNt+dfo66dApFh/7sByJHCGY= 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 5.4 060/168] macsec: avoid to set wrong mtu Date: Tue, 28 Apr 2020 20:23:54 +0200 Message-Id: <20200428182239.519146479@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200428182231.704304409@linuxfoundation.org> References: <20200428182231.704304409@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 @@ -3226,11 +3226,11 @@ static int macsec_newlink(struct net *ne struct netlink_ext_ack *extack) { 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; @@ -3246,7 +3246,11 @@ 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)