From patchwork Thu Apr 23 13:40:47 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Taehee Yoo X-Patchwork-Id: 1275774 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20161025 header.b=tKZEHzON; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 497JNT367lz9sSt for ; Thu, 23 Apr 2020 23:40:57 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728553AbgDWNk4 (ORCPT ); Thu, 23 Apr 2020 09:40:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36176 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1726361AbgDWNk4 (ORCPT ); Thu, 23 Apr 2020 09:40:56 -0400 Received: from mail-pf1-x442.google.com (mail-pf1-x442.google.com [IPv6:2607:f8b0:4864:20::442]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 809DDC08E934 for ; Thu, 23 Apr 2020 06:40:55 -0700 (PDT) Received: by mail-pf1-x442.google.com with SMTP id z1so1266735pfn.3 for ; Thu, 23 Apr 2020 06:40:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=6mkC0WY6HULSFZ8YT/pOSmxeXQvUrcI/s78zoMN0bBw=; b=tKZEHzON1pS583iBymPZK/LWIjEIcs1Bfg/2QBqFsD0EVRuVBxQH+8YEe2AROB6zoa PN9pIY1zm54mPIuRIhdq327qcj3Qgvua9qVaI2KP3/67upstfvB4udcye55xTq2PDQNI bHHAUnNUp7QYDsdRJwKIcQCowaFbvirlSSCxtg0lJNY7m5y+Uh4jdfDo+4i2+Iw8/cHH I/mpc/wCTwLZrlvuDUV2wDBsqP8wdR8S4ER76EUK5vYxCy72as0FE8SS1sAJ/edM5LoN 9T4vyN2W8f5DG+VoILvBunI/Pi7NIHhBy3cHxKRvLmxKAec/KyG3+S8+AjmMegTB+VGl H8Rg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=6mkC0WY6HULSFZ8YT/pOSmxeXQvUrcI/s78zoMN0bBw=; b=ELThn7+UBKsLDTCll+iEFDL76fgcXbu37Ie5ztKr7MYHDOf62OSSMk+d822VmcS5Bj UOLa8eCeDThw4CqCqeknyccncpNS/L9QyN4OkhPiHKeTeivdTNyUtti8m9KXHPKqaInn SNOP3Tikll9HaCMy4jqHTEcazFmkVMiHxGaViBk3C/lJw8q1mXb6oISIS5xN7o6lyyhu ijX+xtp8Iv9Ny/xXmZ8wVu4rEDjnGzT0fYY34kYNXjPhnU2SMjgF9iYjt8YlW2Uq2AGq VXULFleVf2f70ByY4+qzUf+thH3v4XXKPY0ds6HisUbJjV3reCfUoDLvqw10/T76jyWs aBNA== X-Gm-Message-State: AGi0PubVFivdBOSNl0JhUEbWIN32caaO1DNm1iK7XfhkaJbTh7DqPYeU RS/+fc2TNfHcQw3knlSWMP5H+hzhtgM= X-Google-Smtp-Source: APiQypIyIHOkDIDfrxfUYijTQhE3KWaWh2skeBFdJ9gMIg+dmLzZncyCpGHQTc1nB8Z+mYnaeok5Bw== X-Received: by 2002:a62:1b84:: with SMTP id b126mr3796607pfb.123.1587649254834; Thu, 23 Apr 2020 06:40:54 -0700 (PDT) Received: from localhost.localdomain ([180.70.143.152]) by smtp.gmail.com with ESMTPSA id c144sm2560080pfb.172.2020.04.23.06.40.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 23 Apr 2020 06:40:53 -0700 (PDT) From: Taehee Yoo To: davem@davemloft.net, kuba@kernel.org, sd@queasysnail.net, netdev@vger.kernel.org Cc: ap420073@gmail.com Subject: [PATCH net] macsec: avoid to set wrong mtu Date: Thu, 23 Apr 2020 13:40:47 +0000 Message-Id: <20200423134047.21644-1-ap420073@gmail.com> X-Mailer: git-send-email 2.17.1 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org 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 --- 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 a183250ff66a..758baf7cb8a1 100644 --- a/drivers/net/macsec.c +++ b/drivers/net/macsec.c @@ -4002,11 +4002,11 @@ static int macsec_newlink(struct net *net, struct net_device *dev, 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; @@ -4033,7 +4033,11 @@ 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)