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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 C0807C433F5 for ; Sun, 26 Aug 2018 21:23:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 694912170B for ; Sun, 26 Aug 2018 21:23:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 694912170B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=davemloft.net 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 S1727000AbeH0BGm (ORCPT ); Sun, 26 Aug 2018 21:06:42 -0400 Received: from shards.monkeyblade.net ([23.128.96.9]:46176 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726751AbeH0BGm (ORCPT ); Sun, 26 Aug 2018 21:06:42 -0400 Received: from localhost (unknown [70.97.65.230]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id EC156146C38B0; Sun, 26 Aug 2018 14:22:56 -0700 (PDT) Date: Sun, 26 Aug 2018 14:22:52 -0700 (PDT) Message-Id: <20180826.142252.1150683531522716249.davem@davemloft.net> To: keescook@chromium.org Cc: linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk, jhs@mojatatu.com, xiyou.wangcong@gmail.com, jiri@resnulli.us, netdev@vger.kernel.org Subject: Re: [PATCH] net: sched: Fix memory exposure from short TCA_U32_SEL From: David Miller In-Reply-To: <20180826055801.GA42063@beast> References: <20180826055801.GA42063@beast> X-Mailer: Mew version 6.7 on Emacs 26 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Sun, 26 Aug 2018 14:22:57 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Kees Cook Date: Sat, 25 Aug 2018 22:58:01 -0700 > Via u32_change(), TCA_U32_SEL has an unspecified type in the netlink > policy, so max length isn't enforced, only minimum. This means nkeys > (from userspace) was being trusted without checking the actual size of > nla_len(), which could lead to a memory over-read, and ultimately an > exposure via a call to u32_dump(). Reachability is CAP_NET_ADMIN within > a namespace. > > Reported-by: Al Viro > Signed-off-by: Kees Cook I'll apply this as-is and queued it up for -stable. If we want to avoid sizeof(*p) type stuff, it can be done as a follow-up. Thanks.