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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 1F325C433DF for ; Thu, 11 Jun 2020 14:25:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EEC0A2053B for ; Thu, 11 Jun 2020 14:25:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728086AbgFKOZW (ORCPT ); Thu, 11 Jun 2020 10:25:22 -0400 Received: from www62.your-server.de ([213.133.104.62]:57536 "EHLO www62.your-server.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726414AbgFKOZW (ORCPT ); Thu, 11 Jun 2020 10:25:22 -0400 Received: from sslproxy02.your-server.de ([78.47.166.47]) by www62.your-server.de with esmtpsa (TLSv1.2:DHE-RSA-AES256-GCM-SHA384:256) (Exim 4.89_1) (envelope-from ) id 1jjO8t-00082Z-To; Thu, 11 Jun 2020 16:25:20 +0200 Received: from [178.196.57.75] (helo=pc-9.home) by sslproxy02.your-server.de with esmtpsa (TLSv1.3:TLS_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1jjO8t-0006Nr-Ms; Thu, 11 Jun 2020 16:25:19 +0200 Subject: Re: [PATCH bpf v2 0/2] Fix bpf_skb_load_bytes_relative for cgroup_skb/egress To: YiFei Zhu , bpf@vger.kernel.org Cc: Alexei Starovoitov , Stanislav Fomichev , YiFei Zhu References: From: Daniel Borkmann Message-ID: Date: Thu, 11 Jun 2020 16:25:19 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.2 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Authenticated-Sender: daniel@iogearbox.net X-Virus-Scanned: Clear (ClamAV 0.102.3/25840/Thu Jun 11 14:52:31 2020) Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On 6/10/20 8:41 PM, YiFei Zhu wrote: > When cgroup_skb/egress triggers the MAC header is not set. On the other hand, > load_bytes_relative unconditionally calls skb_mac_header which, when MC not > set, returns a pointer after the tail pointer, breaking the logic even if the > caller requested the NET header. > > Fix is to conditionally use skb_mac_header or skb_network_header depending on > the requested header, -EFAULT when the header is not set. Added a test that > asserts during cgroup_skb/egress request for MAC header returns -EFAULT and > request for NET header succeeds. > > Updates since v1: > * Reverted the bound condition check to account for bad offset parameter > larger than data length. > * Add test asssertion for failure return code on the condition above. > > YiFei Zhu (2): > net/filter: Permit reading NET in load_bytes_relative when MAC not set > selftests/bpf: Add cgroup_skb/egress test for load_bytes_relative > > net/core/filter.c | 16 +++-- > .../bpf/prog_tests/load_bytes_relative.c | 71 +++++++++++++++++++ > .../selftests/bpf/progs/load_bytes_relative.c | 48 +++++++++++++ > 3 files changed, 128 insertions(+), 7 deletions(-) > create mode 100644 tools/testing/selftests/bpf/prog_tests/load_bytes_relative.c > create mode 100644 tools/testing/selftests/bpf/progs/load_bytes_relative.c > > -- > 2.27.0 > Applied, thanks!