From patchwork Mon Nov 23 12:23:17 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 331223 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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT 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 D6B13C388F9 for ; Mon, 23 Nov 2020 12:54:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8264520857 for ; Mon, 23 Nov 2020 12:54:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="0XkcCWRP" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387871AbgKWMxT (ORCPT ); Mon, 23 Nov 2020 07:53:19 -0500 Received: from mail.kernel.org ([198.145.29.99]:36850 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387860AbgKWMxH (ORCPT ); Mon, 23 Nov 2020 07:53:07 -0500 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (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 433052168B; Mon, 23 Nov 2020 12:52:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1606135953; bh=x5Cq1URUMwzZhi777AdAVQz03lxHFAXQcXWhhs8r99I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0XkcCWRPKEYRjpJbNNEWzktrqMzGykfyYTpc/yTCra+HwnzpyQ87njsPro1qMo3Vu ENp3JDKZ7TzlFdDvI3Tvtq5bq8gg9un/Zy2t7RhvcvU72MYWmE3HhnZNtO1C1rXZQp 2CZ4YlK7QP3xQ5vefjDmVEmmqrE6mmFrE5SEecp8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Amir Goldstein , Jan Kara Subject: [PATCH 5.9 247/252] fanotify: fix logic of reporting name info with watched parent Date: Mon, 23 Nov 2020 13:23:17 +0100 Message-Id: <20201123121847.506028944@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201123121835.580259631@linuxfoundation.org> References: <20201123121835.580259631@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Amir Goldstein commit 7372e79c9eb9d7034e498721eb2861ae4fdbc618 upstream. The victim inode's parent and name info is required when an event needs to be delivered to a group interested in filename info OR when the inode's parent is interested in an event on its children. Let us call the first condition 'parent_needed' and the second condition 'parent_interested'. In fsnotify_parent(), the condition where the inode's parent is interested in some events on its children, but not necessarily interested the specific event is called 'parent_watched'. fsnotify_parent() tests the condition (!parent_watched && !parent_needed) for sending the event without parent and name info, which is correct. It then wrongly assumes that parent_watched implies !parent_needed and tests the condition (parent_watched && !parent_interested) for sending the event without parent and name info, which is wrong, because parent may still be needed by some group. For example, after initializing a group with FAN_REPORT_DFID_NAME and adding a FAN_MARK_MOUNT with FAN_OPEN mask, open events on non-directory children of "testdir" are delivered with file name info. After adding another mark to the same group on the parent "testdir" with FAN_CLOSE|FAN_EVENT_ON_CHILD mask, open events on non-directory children of "testdir" are no longer delivered with file name info. Fix the logic and use auxiliary variables to clarify the conditions. Fixes: 9b93f33105f5 ("fsnotify: send event with parent/name info to sb/mount/non-dir marks") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20201108105906.8493-1-amir73il@gmail.com Signed-off-by: Amir Goldstein Signed-off-by: Jan Kara Signed-off-by: Greg Kroah-Hartman --- fs/notify/fsnotify.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) --- a/fs/notify/fsnotify.c +++ b/fs/notify/fsnotify.c @@ -178,6 +178,7 @@ int __fsnotify_parent(struct dentry *den struct inode *inode = d_inode(dentry); struct dentry *parent; bool parent_watched = dentry->d_flags & DCACHE_FSNOTIFY_PARENT_WATCHED; + bool parent_needed, parent_interested; __u32 p_mask; struct inode *p_inode = NULL; struct name_snapshot name; @@ -193,7 +194,8 @@ int __fsnotify_parent(struct dentry *den return 0; parent = NULL; - if (!parent_watched && !fsnotify_event_needs_parent(inode, mnt, mask)) + parent_needed = fsnotify_event_needs_parent(inode, mnt, mask); + if (!parent_watched && !parent_needed) goto notify; /* Does parent inode care about events on children? */ @@ -205,17 +207,17 @@ int __fsnotify_parent(struct dentry *den /* * Include parent/name in notification either if some notification - * groups require parent info (!parent_watched case) or the parent is - * interested in this event. + * groups require parent info or the parent is interested in this event. */ - if (!parent_watched || (mask & p_mask & ALL_FSNOTIFY_EVENTS)) { + parent_interested = mask & p_mask & ALL_FSNOTIFY_EVENTS; + if (parent_needed || parent_interested) { /* When notifying parent, child should be passed as data */ WARN_ON_ONCE(inode != fsnotify_data_inode(data, data_type)); /* Notify both parent and child with child name info */ take_dentry_name_snapshot(&name, dentry); file_name = &name.name; - if (parent_watched) + if (parent_interested) mask |= FS_EVENT_ON_CHILD; }