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=-3.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS 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 96E3EC433E0 for ; Tue, 11 Aug 2020 20:56:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 64F802076C for ; Tue, 11 Aug 2020 20:56:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="key not found in DNS" (0-bit key) header.d=szeredi.hu header.i=@szeredi.hu header.b="eKcrw8bQ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726478AbgHKU4b (ORCPT ); Tue, 11 Aug 2020 16:56:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54096 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726405AbgHKU4a (ORCPT ); Tue, 11 Aug 2020 16:56:30 -0400 Received: from mail-ed1-x542.google.com (mail-ed1-x542.google.com [IPv6:2a00:1450:4864:20::542]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D82A5C061788 for ; Tue, 11 Aug 2020 13:56:29 -0700 (PDT) Received: by mail-ed1-x542.google.com with SMTP id bs17so10135675edb.1 for ; Tue, 11 Aug 2020 13:56:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=szeredi.hu; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=mIwwgXuVYR9J8FN3Q7OBMSeO2MRyPkPN2N5o9h2ay8w=; b=eKcrw8bQXY0ON3Tby3NTqixV/DjoLpozBmhQ9Wxh8CrzQKneLuoqFBgMjT6gAHEG5x zYyv+zLUzEwpSrr4OU+QfyjH1a/L/3382mM+GuZnpa9mC47RvCYGIpTbFcfYEHdSy8L3 lYq0C+Xov6wYQlMCdmDB+OTEIdrvHwkv9okCI= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=mIwwgXuVYR9J8FN3Q7OBMSeO2MRyPkPN2N5o9h2ay8w=; b=guxY2TjIdxA4NmqtHBxE5Eyt+NWvLkGExceV90D+ZRtTEfne5U0n6bMmKbbaxMfrhA DPaYAepzcAxSl96iW6zzgbvOUvJ4IJABEmntrKifbRKBF3Z1NCDNm/9BYfliG3ksBIhe XecFVf3uWM1zolvr6Lltikgd3fIt4Qo6l7yZ+X7HqII5Xry4s5S9DDduei2qV4oSaB4I jOFsZhIAH0c5CTUa/zhtJQKCEyf1LqItWmcrM5XczoZ0KRtoaqZlxUVwuuXYN0tDkwWP nxg53R++x0Py/YWRhkAfORIpQR7LZyyc8/qICwa+soGMFc4qdvkOJQmgfUjyVT8teYqj k/mg== X-Gm-Message-State: AOAM530nAkM+Yl6wbNY6DEwI3ghKDma87Z3Xp+IazAJaJK1LSiugQzJB FYG8bQOq0+YUNyjGxdZDq513+mgww6NZyEO0eq82Cg== X-Google-Smtp-Source: ABdhPJy0K+Fs+OPN9rfm6Efrlr92XTN+ignCX68MAQVFzGb3drIK9V+44cU7wIUR+/6aonnP7KkpSeyJKYyxyPce3Ms= X-Received: by 2002:a05:6402:12c4:: with SMTP id k4mr27523537edx.358.1597179388290; Tue, 11 Aug 2020 13:56:28 -0700 (PDT) MIME-Version: 1.0 References: <5C8E0FA8-274E-4B56-9B5A-88E768D01F3A@amacapital.net> In-Reply-To: From: Miklos Szeredi Date: Tue, 11 Aug 2020 22:56:17 +0200 Message-ID: Subject: Re: file metadata via fs API (was: [GIT PULL] Filesystem Information) To: Jann Horn Cc: Casey Schaufler , Andy Lutomirski , Linus Torvalds , linux-fsdevel , David Howells , Al Viro , Karel Zak , Jeff Layton , Miklos Szeredi , Nicolas Dichtel , Christian Brauner , Lennart Poettering , Linux API , Ian Kent , LSM , Linux Kernel Mailing List Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Aug 11, 2020 at 10:37 PM Jann Horn wrote: > If you change the semantics of path strings, you'd have to be > confident that the new semantics fit nicely with all the path > validation routines that exist scattered across userspace, and don't > expose new interfaces through file server software and setuid binaries > and so on. So that's where O_ALT comes in. If the application is consenting, then that should prevent exploits. Or? Thanks, Miklos