From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752081AbcAEQg7 (ORCPT ); Tue, 5 Jan 2016 11:36:59 -0500 Received: from www62.your-server.de ([213.133.104.62]:43046 "EHLO www62.your-server.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751826AbcAEQg4 (ORCPT ); Tue, 5 Jan 2016 11:36:56 -0500 Message-ID: <568BF11F.1060507@iogearbox.net> Date: Tue, 05 Jan 2016 17:36:47 +0100 From: Daniel Borkmann User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 MIME-Version: 1.0 To: Rabin Vincent , davem@davemloft.net CC: netdev@vger.kernel.org, ast@kernel.org, linux-arm-kernel@lists.infradead.org, linux-mips@linux-mips.org, linuxppc-dev@lists.ozlabs.org, sparclinux@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] net: filter: make JITs zero A for SKF_AD_ALU_XOR_X References: <1452007387-626-1-git-send-email-rabin@rab.in> In-Reply-To: <1452007387-626-1-git-send-email-rabin@rab.in> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-Authenticated-Sender: daniel@iogearbox.net Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/05/2016 04:23 PM, Rabin Vincent wrote: > The SKF_AD_ALU_XOR_X ancillary is not like the other ancillary data > instructions since it XORs A with X while all the others replace A with > some loaded value. All the BPF JITs fail to clear A if this is used as > the first instruction in a filter. This was found using american fuzzy > lop. > > Add a helper to determine if A needs to be cleared given the first > instruction in a filter, and use this in the JITs. Except for ARM, the > rest have only been compile-tested. > > Fixes: 3480593131e0 ("net: filter: get rid of BPF_S_* enum") > Signed-off-by: Rabin Vincent Excellent catch, thanks a lot! The fix looks good to me and should go to -net tree. Acked-by: Daniel Borkmann If you're interested, feel free to add a small test case for the SKF_AD_ALU_XOR_X issue to lib/test_bpf.c for -net-next tree. Thanks!