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=-13.0 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FSL_HELO_FAKE,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT, USER_IN_DEF_DKIM_WL autolearn=ham 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 6E382C04A6B for ; Fri, 10 May 2019 21:28:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3C72B217F9 for ; Fri, 10 May 2019 21:28:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="OpeS/e5y" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728153AbfEJV2k (ORCPT ); Fri, 10 May 2019 17:28:40 -0400 Received: from mail-ed1-f68.google.com ([209.85.208.68]:32980 "EHLO mail-ed1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728160AbfEJV2k (ORCPT ); Fri, 10 May 2019 17:28:40 -0400 Received: by mail-ed1-f68.google.com with SMTP id n17so6964376edb.0 for ; Fri, 10 May 2019 14:28:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=ULvb6m5Ct7N+U+Hk+TL0VPodYz5yvNtcE2Pdidu8130=; b=OpeS/e5yAb8uvpLXYNqA6N1MI8D7JXLjmHyNft0qks+8R/zc45m3XbQH7ZLcDfretb NJx/g0yV7jox/sIORLwOrxO1a9CV1jZa4gZ98sX8gwy7R8ojzc6s0LmwQEN7UABbk8mb Fxhe8bCtYUg4ePrk9piZU6axZgBrTRfXt2Nca9QBNovg68zQtj8GUi/rd7SCaOGE7XQG maBuJVPgPv8M7/MFnTidvVHklN5G7hqvUjLYWauPMuQewufDa3+DR5c2bfu6JIzKNOi0 rmTdxIt5cPg9YEIjCngJ1xtbJ4MWbtHDYD1wkUYVwYJKhe+0vPHojo8IZxOQPW4XrFjy V9dA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=ULvb6m5Ct7N+U+Hk+TL0VPodYz5yvNtcE2Pdidu8130=; b=c4mAuJGgwV1GAaODUwmoqVQ/fJafkdK8fUo22cjS7JC2ufK1v3bwMcgbctAGQDq7zM OVAqPpEDrFHf8IJNjM6k641JDhBE1D0iQSS23duN0vS3EO8FPxfR6LDgUbcqgawMYCym UEs25rvUrCi350DWj4gH2+/FISSDuKbsdAnpQ1/0ymnAr2JWbQ49eMG7L8QBdN9auuHw sqfGV/GKom9RSIpAZFZG7yRvF52/OcCLFhFT2xcwe1rTxICjsdz8rFaQcYoY8emkC1bN 8SLGsPEsgz2SD71atdWAnWcz7W3DkS4tfbE4XOiM3ah8inwrFcxXXae4f+vMLsddCMSm 5MhQ== X-Gm-Message-State: APjAAAVkZY3O2txxkg2fM1VgrdRjwznAxM8OFZFkIhSOaknHFT6IOSre NDvy08QmH+Tp5XjOJpI6A3t0Ng== X-Google-Smtp-Source: APXvYqwB8IbdmimHYeSIRTDySy1Eup7HC96peg+2fx8bMgd82d1e5doTbK2hNZI5/C/ZsrOzqlCN9w== X-Received: by 2002:a50:f5d0:: with SMTP id x16mr13446339edm.287.1557523718509; Fri, 10 May 2019 14:28:38 -0700 (PDT) Received: from google.com ([2a00:79e0:1b:201:ee0a:cce3:df40:3ac5]) by smtp.gmail.com with ESMTPSA id c6sm1742858edk.81.2019.05.10.14.28.36 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Fri, 10 May 2019 14:28:37 -0700 (PDT) Date: Fri, 10 May 2019 23:28:31 +0200 From: Jann Horn To: Roberto Sassu Cc: viro@zeniv.linux.org.uk, linux-security-module@vger.kernel.org, linux-integrity@vger.kernel.org, initramfs@vger.kernel.org, linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, zohar@linux.vnet.ibm.com, silviu.vlasceanu@huawei.com, dmitry.kasatkin@huawei.com, takondra@cisco.com, kamensky@cisco.com, hpa@zytor.com, arnd@arndb.de, rob@landley.net, james.w.mcmechan@gmail.com Subject: Re: [PATCH v2 1/3] fs: add ksys_lsetxattr() wrapper Message-ID: <20190510212831.GD253532@google.com> References: <20190509112420.15671-1-roberto.sassu@huawei.com> <20190509112420.15671-2-roberto.sassu@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190509112420.15671-2-roberto.sassu@huawei.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-integrity-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org On Thu, May 09, 2019 at 01:24:18PM +0200, Roberto Sassu wrote: > Similarly to commit 03450e271a16 ("fs: add ksys_fchmod() and do_fchmodat() > helpers and ksys_chmod() wrapper; remove in-kernel calls to syscall"), this > patch introduces the ksys_lsetxattr() helper to avoid in-kernel calls to > the sys_lsetxattr() syscall. > > Signed-off-by: Roberto Sassu [...] > +int ksys_lsetxattr(const char __user *pathname, > + const char __user *name, const void __user *value, > + size_t size, int flags) > +{ > + return path_setxattr(pathname, name, value, size, flags, 0); > +} Instead of exposing ksys_lsetxattr(), wouldn't it be cleaner to use kern_path() and vfs_setxattr(), or something like that? Otherwise you're adding more code that has to cast between kernel and user pointers.