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=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 0F08FC433FF for ; Wed, 7 Aug 2019 13:52:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D74E522295 for ; Wed, 7 Aug 2019 13:52:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=amacapital-net.20150623.gappssmtp.com header.i=@amacapital-net.20150623.gappssmtp.com header.b="hvFXtVNZ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729804AbfHGNwk (ORCPT ); Wed, 7 Aug 2019 09:52:40 -0400 Received: from mail-pl1-f194.google.com ([209.85.214.194]:44681 "EHLO mail-pl1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729712AbfHGNwk (ORCPT ); Wed, 7 Aug 2019 09:52:40 -0400 Received: by mail-pl1-f194.google.com with SMTP id t14so40903330plr.11 for ; Wed, 07 Aug 2019 06:52:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amacapital-net.20150623.gappssmtp.com; s=20150623; h=mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=QnyCTyMbm52NNTF3jvsG/XFHwGBN7xSjxw+ALsjB1gk=; b=hvFXtVNZhyN0kdv9iaA7yZN5RqEBCjciXVvNLIybGo9HT7b3b+wEhDXgwXt9UF8Mrn eZN37QzXBNaCRPUTOtvLbduEWeOl25BDcGmYWV9ZLZmyIY2DelXEGI0guJ8ZqYDWCUc+ Uq07GDbvjCnmuho1/UwA+WeZD6IjYNeymq8uFSzW05d1Kn5WjcoE/sdiEk4q9Pnv4DZG rGzgQi4Dw5txGWJVOLLOOxkaXvyGLKhZ4QawFZhVwDTHvgFIyA6iWIhIz3gscwe8DFor gFkbJ3pleEF/BzQx06R1m0tmzKsGUUbphwQkDn43e/6Z8P/hMPwnuj+yzSMhfPUJT3ph I76g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=QnyCTyMbm52NNTF3jvsG/XFHwGBN7xSjxw+ALsjB1gk=; b=l+DWTGJQhOP8BKY+B/oCVKo+2w+sMZfbAFdQ13bxVQWbWohXWSwcwN8oHl3UYQ4wW4 peXgYnthRT4mveRg+0FDHPXd9DTWgbZ4T6aUEDlOUs8sMIrhKMificCdi6JZ2jxFxT8t z82vNJSfUj+Sc5RKqOeQSMS/fTXFCDwhT4X/qpVS9/5wwc2akTWUuHbG2SXwwnkwr5zi EJFWgHOT8wcWWwLLlwG6uhAzzMM5pUnORP9+QNAVPdnXaM/kWrW955bDQhOboAuMboGl A5cLFKRM50dTwySo0TDrXIdwmhn/hc/b3j8j2a8Ut9u2YykPgVDyYyzjAaQvRuxA5iTZ NnXA== X-Gm-Message-State: APjAAAW0g7uUS2IShctPlyXAeJMPqzvb1UpoX4PGuZvnoxavwwLoyoQA truVpONbWPZ8gJpm/cLFYJbTxQ== X-Google-Smtp-Source: APXvYqyZHqBPVgXKeTfuam/+wr//DWw1+la2CyEt/5QA6T/uZGoDWyT0btIOkYHc/WOyvZTCa5PcRg== X-Received: by 2002:aa7:9dcd:: with SMTP id g13mr9657897pfq.204.1565185959443; Wed, 07 Aug 2019 06:52:39 -0700 (PDT) Received: from ?IPv6:2601:646:c200:1ef2:e49d:f1dd:cb7c:c8f6? ([2601:646:c200:1ef2:e49d:f1dd:cb7c:c8f6]) by smtp.gmail.com with ESMTPSA id q69sm130734pjb.0.2019.08.07.06.52.37 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 07 Aug 2019 06:52:37 -0700 (PDT) Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (1.0) Subject: Re: [PATCH v2 bpf-next 1/4] bpf: unprivileged BPF access via /dev/bpf From: Andy Lutomirski X-Mailer: iPhone Mail (16G77) In-Reply-To: Date: Wed, 7 Aug 2019 06:52:36 -0700 Cc: Andy Lutomirski , Alexei Starovoitov , Song Liu , Kees Cook , Networking , bpf , Alexei Starovoitov , Daniel Borkmann , Kernel Team , Jann Horn , Greg KH , Linux API , LSM List Content-Transfer-Encoding: quoted-printable Message-Id: <945BCF23-839C-418C-9FBF-46889AE84CA4@amacapital.net> References: <5A2FCD7E-7F54-41E5-BFAE-BB9494E74F2D@fb.com> <20190805192122.laxcaz75k4vxdspn@ast-mbp> <20190806011134.p5baub5l3t5fkmou@ast-mbp> To: Lorenz Bauer Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: > On Aug 7, 2019, at 2:03 AM, Lorenz Bauer wrote: >=20 >> On Wed, 7 Aug 2019 at 06:24, Andy Lutomirski wrote: >> a) Those that, by design, control privileged operations. This >> includes most attach calls, but it also includes allow_ptr_leaks, >> bpf_probe_read(), and quite a few other things. It also includes all >> of the by_id calls, I think, unless some clever modification to the >> way they worked would isolate different users' objects. I think that >> persistent objects can do pretty much everything that by_id users >> would need, so this isn't a big deal. >=20 > Slightly OT, since this is an implementation question: GET_MAP_FD_BY_ID > is useful to iterate a nested map. This isn't covered by rights to > persistent objects, > so it would need some thought. >=20 >=20 A call to get an fd to a map referenced by a map to which you already have a= n fd seems reasonable to me. The new fd would inherit the old fd=E2=80=99s a= ccess mode.=