From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paul Moore Subject: Re: [PATCH 2/3] [RFC] seccomp: give BPF x32 bit when restoring x32 filter Date: Fri, 11 Jul 2014 12:11:37 -0400 Message-ID: <1458762.ra4TnS54ZN@sifl> References: <6a69eb94b4cfac5f94b229c2eb2ebc402aac722a.1405023592.git.rgb@redhat.com> <53BF62AA.20105@zytor.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Return-path: In-Reply-To: <53BF62AA.20105@zytor.com> Sender: linux-kernel-owner@vger.kernel.org To: "H. Peter Anvin" Cc: Richard Guy Briggs , linux-audit@redhat.com, linux-kernel@vger.kernel.org, Eric Paris , Al Viro , Will Drewry List-Id: linux-audit@redhat.com On Thursday, July 10, 2014 09:06:02 PM H. Peter Anvin wrote: > Incidentally: do seccomp users know that on an x86-64 system you can > recevie system calls from any of the x86 architectures, regardless of > how the program is invoked? (This is unusual, so normally denying those > "alien" calls is the right thing to do.) I obviously can't speak for all seccomp users, but libseccomp handles this by checking the seccomp_data->arch value at the start of the filter and killing (by default) any non-native architectures. If you want, you can change this default behavior or add support for other architectures (e.g. create a filter that allows both x86-64 and x32 but disallows x86, or any combination of the three for that matter). -- paul moore security and virtualization @ redhat