From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752520AbdHIBLi convert rfc822-to-8bit (ORCPT ); Tue, 8 Aug 2017 21:11:38 -0400 Received: from shards.monkeyblade.net ([184.105.139.130]:58364 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751971AbdHIBLe (ORCPT ); Tue, 8 Aug 2017 21:11:34 -0400 Date: Tue, 08 Aug 2017 18:11:33 -0700 (PDT) Message-Id: <20170808.181133.1654188772199067010.davem@davemloft.net> To: mic@digikod.net Cc: linux-kernel@vger.kernel.org, ast@fb.com, daniel@iogearbox.net, keescook@chromium.org, kafai@fb.com, netdev@vger.kernel.org, ast@kernel.org Subject: Re: [PATCH net-next v2 2/2] bpf: Extend check_uarg_tail_zero() checks From: David Miller In-Reply-To: <20170807184520.8130-2-mic@digikod.net> References: <20170807184520.8130-1-mic@digikod.net> <20170807184520.8130-2-mic@digikod.net> X-Mailer: Mew version 6.7 on Emacs 25.2 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=iso-8859-1 Content-Transfer-Encoding: 8BIT X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Tue, 08 Aug 2017 18:11:34 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Mickaël Salaün Date: Mon, 7 Aug 2017 20:45:20 +0200 > The function check_uarg_tail_zero() was created from bpf(2) for > BPF_OBJ_GET_INFO_BY_FD without taking the access_ok() nor the PAGE_SIZE > checks. Make this checks more generally available while unlikely to be > triggered, extend the memory range check and add an explanation > including why the ToCToU should not be a security concern. > > Signed-off-by: Mickaël Salaün > Acked-by: Daniel Borkmann > Cc: Alexei Starovoitov > Cc: David S. Miller > Cc: Kees Cook > Cc: Martin KaFai Lau > Link: https://lkml.kernel.org/r/CAGXu5j+vRGFvJZmjtAcT8Hi8B+Wz0e1b6VKYZHfQP_=DXzC4CQ@mail.gmail.com Applied.