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,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 630B5C5DF60 for ; Fri, 8 Nov 2019 11:59:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3AC412084D for ; Fri, 8 Nov 2019 11:59:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573214372; bh=5y7jySM1EY7FEWm+rSzD2iseCEIB0/ban7fS0k4+TEA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Ay9OjtZOXI5qRN+IYN6CKXe+RnWnf7Ue/o2esxiwU1gvreOPsbmN7sa9/cXeFLuj+ HzxBfjxBwYfiYLPeXwBCCx9f6fC6KwFivAqCDAhvpZdT5G2LJ6pDilqOGAi7K/E21y RapNzOdp8GGc+069rIDNUQ2pS+6amuUpRB0seAOg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733257AbfKHL71 (ORCPT ); Fri, 8 Nov 2019 06:59:27 -0500 Received: from mail.kernel.org ([198.145.29.99]:59050 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389081AbfKHLoM (ORCPT ); Fri, 8 Nov 2019 06:44:12 -0500 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 A5FDF21D82; Fri, 8 Nov 2019 11:44:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573213451; bh=5y7jySM1EY7FEWm+rSzD2iseCEIB0/ban7fS0k4+TEA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xB5ZKhuEwLL3DvBsRxoo7BG7So4ogzWgNAd/1nvlmBepbMEsmy85UeJ6/rT7zR0Or aq4e7TPHLk8Q1hpBKQCECp5/wgkL815betMAZbXnk+QhKrIVtYS4t2dpz+I7cPPGk/ dOeH0jgDa4HbxfZGudeiGcw09kJUNl9xaosq0Q00= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Muhammad Sammar , Feras Daoud , Leon Romanovsky , Jason Gunthorpe , Sasha Levin , linux-rdma@vger.kernel.org Subject: [PATCH AUTOSEL 4.14 043/103] IB/ipoib: Ensure that MTU isn't less than minimum permitted Date: Fri, 8 Nov 2019 06:42:08 -0500 Message-Id: <20191108114310.14363-43-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191108114310.14363-1-sashal@kernel.org> References: <20191108114310.14363-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-rdma-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org From: Muhammad Sammar [ Upstream commit 142a9c287613560edf5a03c8d142c8b6ebc1995b ] It is illegal to change MTU to a value lower than the minimum MTU stated in ethernet spec. In addition to that we need to add 4 bytes for encapsulation header (IPOIB_ENCAP_LEN). Before "ifconfig ib0 mtu 0" command, succeeds while it obviously shouldn't. Signed-off-by: Muhammad Sammar Reviewed-by: Feras Daoud Signed-off-by: Leon Romanovsky Signed-off-by: Jason Gunthorpe Signed-off-by: Sasha Levin --- drivers/infiniband/ulp/ipoib/ipoib_main.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/infiniband/ulp/ipoib/ipoib_main.c b/drivers/infiniband/ulp/ipoib/ipoib_main.c index 1a93d3d58c8a4..caae4bfab950d 100644 --- a/drivers/infiniband/ulp/ipoib/ipoib_main.c +++ b/drivers/infiniband/ulp/ipoib/ipoib_main.c @@ -249,7 +249,8 @@ static int ipoib_change_mtu(struct net_device *dev, int new_mtu) return 0; } - if (new_mtu > IPOIB_UD_MTU(priv->max_ib_mtu)) + if (new_mtu < (ETH_MIN_MTU + IPOIB_ENCAP_LEN) || + new_mtu > IPOIB_UD_MTU(priv->max_ib_mtu)) return -EINVAL; priv->admin_mtu = new_mtu; -- 2.20.1