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=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 B6C5FC432C0 for ; Fri, 22 Nov 2019 06:04:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8F4B820674 for ; Fri, 22 Nov 2019 06:04:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574402655; bh=3pT4tzAQDoCWy1rARRfevvK6RgLlOffebbAAx/Ips6Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=KFtlk8CMeCDPUmvUyS1xNQPTKqOsJF3WFxGOcJ6kpeDqzkDXu41wsUoBcPAgEf337 Y8RHQWlpNSwpVWuwbCwOGD2wj2C4eWCL0IkBsgk+LJj36DeUYi4M/r8KK7mxaWGIrH v+7q2ct+yhHrckoPYICPmcQ87v1MDLmqBGbzvrXA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727096AbfKVGEO (ORCPT ); Fri, 22 Nov 2019 01:04:14 -0500 Received: from mail.kernel.org ([198.145.29.99]:41878 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729419AbfKVGC7 (ORCPT ); Fri, 22 Nov 2019 01:02:59 -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 C74312070E; Fri, 22 Nov 2019 06:02:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574402578; bh=3pT4tzAQDoCWy1rARRfevvK6RgLlOffebbAAx/Ips6Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WnSQUM8YrrpdMuccbEqpXVnukf89I0YC7Rveg/+k2XI7x/YH5updkAJuUy050BLEv M9cV63x4HxlWmw0DClYLzIYjKfM2Ir3FZ+2epG3hO55+lVZb268OYGCd6qaTiI4rNx DbFljBxnKVUmai2wvwn7x895sxez7Khiljtqt/jc= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Johannes Berg , "David S . Miller" , Sasha Levin , linux-decnet-user@lists.sourceforge.net, netdev@vger.kernel.org Subject: [PATCH AUTOSEL 4.9 80/91] decnet: fix DN_IFREQ_SIZE Date: Fri, 22 Nov 2019 01:01:18 -0500 Message-Id: <20191122060129.4239-79-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191122060129.4239-1-sashal@kernel.org> References: <20191122060129.4239-1-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: Johannes Berg [ Upstream commit 50c2936634bcb1db78a8ca63249236810c11a80f ] Digging through the ioctls with Al because of the previous patches, we found that on 64-bit decnet's dn_dev_ioctl() is wrong, because struct ifreq::ifr_ifru is actually 24 bytes (not 16 as expected from struct sockaddr) due to the ifru_map and ifru_settings members. Clearly, decnet expects the ioctl to be called with a struct like struct ifreq_dn { char ifr_name[IFNAMSIZ]; struct sockaddr_dn ifr_addr; }; since it does struct ifreq *ifr = ...; struct sockaddr_dn *sdn = (struct sockaddr_dn *)&ifr->ifr_addr; This means that DN_IFREQ_SIZE is too big for what it wants on 64-bit, as it is sizeof(struct ifreq) - sizeof(struct sockaddr) + sizeof(struct sockaddr_dn) This assumes that sizeof(struct sockaddr) is the size of ifr_ifru but that isn't true. Fix this to use offsetof(struct ifreq, ifr_ifru). This indeed doesn't really matter much - the result is that we copy in/out 8 bytes more than we should on 64-bit platforms. In case the "struct ifreq_dn" lands just on the end of a page though it might lead to faults. As far as I can tell, it has been like this forever, so it seems very likely that nobody cares. Signed-off-by: Johannes Berg Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/decnet/dn_dev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/decnet/dn_dev.c b/net/decnet/dn_dev.c index b2c26b081134a..80554e7e9a0f6 100644 --- a/net/decnet/dn_dev.c +++ b/net/decnet/dn_dev.c @@ -55,7 +55,7 @@ #include #include -#define DN_IFREQ_SIZE (sizeof(struct ifreq) - sizeof(struct sockaddr) + sizeof(struct sockaddr_dn)) +#define DN_IFREQ_SIZE (offsetof(struct ifreq, ifr_ifru) + sizeof(struct sockaddr_dn)) static char dn_rt_all_end_mcast[ETH_ALEN] = {0xAB,0x00,0x00,0x04,0x00,0x00}; static char dn_rt_all_rt_mcast[ETH_ALEN] = {0xAB,0x00,0x00,0x03,0x00,0x00}; -- 2.20.1