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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 AE189CA9EB9 for ; Sat, 26 Oct 2019 19:40:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8F77C206DD for ; Sat, 26 Oct 2019 19:40:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726462AbfJZTkd (ORCPT ); Sat, 26 Oct 2019 15:40:33 -0400 Received: from smtprelay0186.hostedemail.com ([216.40.44.186]:42911 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726342AbfJZTkd (ORCPT ); Sat, 26 Oct 2019 15:40:33 -0400 Received: from filter.hostedemail.com (clb03-v110.bra.tucows.net [216.40.38.60]) by smtprelay05.hostedemail.com (Postfix) with ESMTP id 3C59D180357D1; Sat, 26 Oct 2019 19:40:31 +0000 (UTC) X-Session-Marker: 6A6F6540706572636865732E636F6D X-HE-Tag: stone20_785fe5ad57825 X-Filterd-Recvd-Size: 3871 Received: from XPS-9350.home (unknown [47.151.135.224]) (Authenticated sender: joe@perches.com) by omf12.hostedemail.com (Postfix) with ESMTPA; Sat, 26 Oct 2019 19:40:27 +0000 (UTC) Message-ID: Subject: Re: [PATCH] net: Zeroing the structure ethtool_wolinfo in ethtool_get_wol() From: Joe Perches To: zhanglin , davem@davemloft.net, cocci , Andrew Morton , Thomas Gleixner , Linus Torvalds Cc: ast@kernel.org, daniel@iogearbox.net, jakub.kicinski@netronome.com, hawk@kernel.org, john.fastabend@gmail.com, mkubecek@suse.cz, jiri@mellanox.com, pablo@netfilter.org, f.fainelli@gmail.com, maxime.chevallier@bootlin.com, lirongqing@baidu.com, vivien.didelot@gmail.com, linyunsheng@huawei.com, natechancellor@gmail.com, arnd@arndb.de, dan.carpenter@oracle.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, xue.zhihong@zte.com.cn, wang.yi59@zte.com.cn, jiang.xuexin@zte.com.cn Date: Sat, 26 Oct 2019 12:40:23 -0700 In-Reply-To: <1572076456-12463-1-git-send-email-zhang.lin16@zte.com.cn> References: <1572076456-12463-1-git-send-email-zhang.lin16@zte.com.cn> Content-Type: text/plain; charset="ISO-8859-1" User-Agent: Evolution 3.34.1-2 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Sat, 2019-10-26 at 15:54 +0800, zhanglin wrote: > memset() the structure ethtool_wolinfo that has padded bytes > but the padded bytes have not been zeroed out. [] > diff --git a/net/core/ethtool.c b/net/core/ethtool.c [] > @@ -1471,11 +1471,13 @@ static int ethtool_reset(struct net_device *dev, char __user *useraddr) > > static int ethtool_get_wol(struct net_device *dev, char __user *useraddr) > { > - struct ethtool_wolinfo wol = { .cmd = ETHTOOL_GWOL }; > + struct ethtool_wolinfo wol; > > if (!dev->ethtool_ops->get_wol) > return -EOPNOTSUPP; > > + memset(&wol, 0, sizeof(struct ethtool_wolinfo)); > + wol.cmd = ETHTOOL_GWOL; > dev->ethtool_ops->get_wol(dev, &wol); > > if (copy_to_user(useraddr, &wol, sizeof(wol))) It seems likely there are more of these. Is there any way for coccinelle to find them? There are ~4000 structs in include/uapi and there are ~3000 uses of copy_to_user in the tree. $ git grep -P '\bstruct\s+\w+\s*{' include/uapi/ | cut -f2 -d" "|sort|uniq|wc -l 3785 $ git grep -w copy_to_user|wc -l 2854 A trivial grep and manual search using: $ git grep -B20 -w copy_to_user | grep -A20 -P '\bstruct\s+\w+\s*=\s*{' shows at least 1 (I didn't look very hard and stopped after finding 1): include/uapi/linux/utsname.h:struct oldold_utsname { include/uapi/linux/utsname.h- char sysname[9]; include/uapi/linux/utsname.h- char nodename[9]; include/uapi/linux/utsname.h- char release[9]; include/uapi/linux/utsname.h- char version[9]; include/uapi/linux/utsname.h- char machine[9]; include/uapi/linux/utsname.h-}; and kernel/sys.c- struct oldold_utsname tmp = {}; kernel/sys.c- kernel/sys.c- if (!name) kernel/sys.c- return -EFAULT; kernel/sys.c- kernel/sys.c- down_read(&uts_sem); kernel/sys.c- memcpy(&tmp.sysname, &utsname()->sysname, __OLD_UTS_LEN); kernel/sys.c- memcpy(&tmp.nodename, &utsname()->nodename, __OLD_UTS_LEN); kernel/sys.c- memcpy(&tmp.release, &utsname()->release, __OLD_UTS_LEN); kernel/sys.c- memcpy(&tmp.version, &utsname()->version, __OLD_UTS_LEN); kernel/sys.c- memcpy(&tmp.machine, &utsname()->machine, __OLD_UTS_LEN); kernel/sys.c- up_read(&uts_sem); kernel/sys.c: if (copy_to_user(name, &tmp, sizeof(tmp))) where there is likely 3 bytes of padding after 45 bytes of data in the struct.