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=-5.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS, T_DKIMWL_WL_HIGH,URIBL_BLOCKED,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 6BAADC65C22 for ; Fri, 2 Nov 2018 18:44:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 17D4A20847 for ; Fri, 2 Nov 2018 18:44:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="jCaE57aP" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 17D4A20847 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730000AbeKCDwL (ORCPT ); Fri, 2 Nov 2018 23:52:11 -0400 Received: from mail.kernel.org ([198.145.29.99]:47456 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726849AbeKCDwK (ORCPT ); Fri, 2 Nov 2018 23:52:10 -0400 Received: from localhost (5356596B.cm-6-7b.dynamic.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 4456220847; Fri, 2 Nov 2018 18:43:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1541184237; bh=dpZkfPrg9larV5EtNTu1msmcHHQKvRGZW63YcXvCjSU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jCaE57aPTPJDqnua7+gB17r+c5KKTQAhf/jGNmMVKNk0pzMwu4YIx9NEV3pAr7o05 VMEWvgCzkJvLheUW8OhJDejmbHo4ub7Xhl8DAY+dvxz9lzOJgbPKBEkFUCphEw+pPz sMtGF9xrDcfLk0TFzYQ2iCmNeAbjPAUm5hI39Rm8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Wenwen Wang , "David S. Miller" Subject: [PATCH 4.18 112/150] net: socket: fix a missing-check bug Date: Fri, 2 Nov 2018 19:34:34 +0100 Message-Id: <20181102182910.978994735@linuxfoundation.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181102182902.250560510@linuxfoundation.org> References: <20181102182902.250560510@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review 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 4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Wenwen Wang [ Upstream commit b6168562c8ce2bd5a30e213021650422e08764dc ] In ethtool_ioctl(), the ioctl command 'ethcmd' is checked through a switch statement to see whether it is necessary to pre-process the ethtool structure, because, as mentioned in the comment, the structure ethtool_rxnfc is defined with padding. If yes, a user-space buffer 'rxnfc' is allocated through compat_alloc_user_space(). One thing to note here is that, if 'ethcmd' is ETHTOOL_GRXCLSRLALL, the size of the buffer 'rxnfc' is partially determined by 'rule_cnt', which is actually acquired from the user-space buffer 'compat_rxnfc', i.e., 'compat_rxnfc->rule_cnt', through get_user(). After 'rxnfc' is allocated, the data in the original user-space buffer 'compat_rxnfc' is then copied to 'rxnfc' through copy_in_user(), including the 'rule_cnt' field. However, after this copy, no check is re-enforced on 'rxnfc->rule_cnt'. So it is possible that a malicious user race to change the value in the 'compat_rxnfc->rule_cnt' between these two copies. Through this way, the attacker can bypass the previous check on 'rule_cnt' and inject malicious data. This can cause undefined behavior of the kernel and introduce potential security risk. This patch avoids the above issue via copying the value acquired by get_user() to 'rxnfc->rule_cn', if 'ethcmd' is ETHTOOL_GRXCLSRLALL. Signed-off-by: Wenwen Wang Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/socket.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) --- a/net/socket.c +++ b/net/socket.c @@ -2887,9 +2887,14 @@ static int ethtool_ioctl(struct net *net copy_in_user(&rxnfc->fs.ring_cookie, &compat_rxnfc->fs.ring_cookie, (void __user *)(&rxnfc->fs.location + 1) - - (void __user *)&rxnfc->fs.ring_cookie) || - copy_in_user(&rxnfc->rule_cnt, &compat_rxnfc->rule_cnt, - sizeof(rxnfc->rule_cnt))) + (void __user *)&rxnfc->fs.ring_cookie)) + return -EFAULT; + if (ethcmd == ETHTOOL_GRXCLSRLALL) { + if (put_user(rule_cnt, &rxnfc->rule_cnt)) + return -EFAULT; + } else if (copy_in_user(&rxnfc->rule_cnt, + &compat_rxnfc->rule_cnt, + sizeof(rxnfc->rule_cnt))) return -EFAULT; }