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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 B9DFCC4360F for ; Thu, 4 Apr 2019 13:39:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 96D14214AF for ; Thu, 4 Apr 2019 13:39:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729244AbfDDNjL (ORCPT ); Thu, 4 Apr 2019 09:39:11 -0400 Received: from mail.kernel.org ([198.145.29.99]:36692 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726790AbfDDNjL (ORCPT ); Thu, 4 Apr 2019 09:39:11 -0400 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 66F6220855; Thu, 4 Apr 2019 13:39:09 +0000 (UTC) Date: Thu, 4 Apr 2019 09:39:07 -0400 From: Steven Rostedt To: Matthew Garrett Cc: jmorris@namei.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, dhowells@redhat.com, linux-api@vger.kernel.org, luto@kernel.org, Matthew Garrett Subject: Re: [PATCH V32 27/27] tracefs: Restrict tracefs when the kernel is locked down Message-ID: <20190404093907.153f52a8@gandalf.local.home> In-Reply-To: <20190404003249.14356-28-matthewgarrett@google.com> References: <20190404003249.14356-1-matthewgarrett@google.com> <20190404003249.14356-28-matthewgarrett@google.com> X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 3 Apr 2019 17:32:49 -0700 Matthew Garrett wrote: > +static void tracefs_destroy_inode(struct inode *inode) > +{ > + if S_ISREG(inode->i_mode) Can we please put parenthesis around the condition. I know that the macro has them, but no other place in the kernel plays such a trick. if (S_ISREG(inode->i_mode)) Other than that, the rest looks good. Reviewed-by: Steven Rostedt (VMware) -- Steve > + kfree(inode->i_fop); > +} > + > static int tracefs_remount(struct super_block *sb, int *flags, char *data) > { > int err; > @@ -260,6 +288,7 @@ static int tracefs_show_options(struct seq_file *m, struct dentry *root) > > static const struct super_operations tracefs_super_operations = { > .statfs = simple_statfs, > + .destroy_inode = tracefs_destroy_inode, > .remount_fs = tracefs_remount, > .show_options = tracefs_show_options, > }; > @@ -393,6 +422,7 @@ struct dentry *tracefs_create_file(const char *name, umode_t mode, > { > struct dentry *dentry; > struct inode *inode; > + struct file_operations *proxy_fops; > > if (!(mode & S_IFMT)) > mode |= S_IFREG; > @@ -406,8 +436,16 @@ struct dentry *tracefs_create_file(const char *name, umode_t mode, > if (unlikely(!inode)) > return failed_creating(dentry); > > + proxy_fops = kzalloc(sizeof(struct file_operations), GFP_KERNEL); > + if (!proxy_fops) > + return failed_creating(dentry); > + > + dentry->d_fsdata = fops ? (void *)fops : > + (void *)&tracefs_file_operations; > + memcpy(proxy_fops, dentry->d_fsdata, sizeof(struct file_operations)); > + proxy_fops->open = default_open_file; > inode->i_mode = mode; > - inode->i_fop = fops ? fops : &tracefs_file_operations; > + inode->i_fop = proxy_fops; > inode->i_private = data; > d_instantiate(dentry, inode); > fsnotify_create(dentry->d_parent->d_inode, dentry);