From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:34892 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751567AbcBMXD3 (ORCPT ); Sat, 13 Feb 2016 18:03:29 -0500 Subject: Patch "tracefs: Fix refcount imbalance in start_creating()" has been added to the 4.3-stable tree To: daniel@iogearbox.net, gregkh@linuxfoundation.org, rostedt@goodmis.org Cc: , From: Date: Sat, 13 Feb 2016 15:03:27 -0800 Message-ID: <14554046073103@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled tracefs: Fix refcount imbalance in start_creating() to the 4.3-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: tracefs-fix-refcount-imbalance-in-start_creating.patch and it can be found in the queue-4.3 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From d227c3ae4e94e5eb11dd780a811f59e1a7b74ccd Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Wed, 4 Nov 2015 23:33:17 +0100 Subject: tracefs: Fix refcount imbalance in start_creating() From: Daniel Borkmann commit d227c3ae4e94e5eb11dd780a811f59e1a7b74ccd upstream. In tracefs' start_creating(), we pin the file system to safely access its root. When we failed to create a file, we unpin the file system via failed_creating() to release the mount count and eventually the reference of the singleton vfsmount. However, when we run into an error during lookup_one_len() when still in start_creating(), we only release the parent's mutex but not so the reference on the mount. F.e., in securityfs_create_file(), after doing simple_pin_fs() when lookup_one_len() fails there, we infact do simple_release_fs(). This seems necessary here as well. Same issue seen in debugfs due to 190afd81e4a5 ("debugfs: split the beginning and the end of __create_file() off"), which seemed to got carried over into tracefs, too. Noticed during code review. Link: http://lkml.kernel.org/r/68efa86101b778cf7517ed7c6ad573bd69f60ec6.1446672850.git.daniel@iogearbox.net Fixes: 4282d60689d4 ("tracefs: Add new tracefs file system") Signed-off-by: Daniel Borkmann Signed-off-by: Steven Rostedt Signed-off-by: Greg Kroah-Hartman --- fs/tracefs/inode.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/fs/tracefs/inode.c +++ b/fs/tracefs/inode.c @@ -340,8 +340,12 @@ static struct dentry *start_creating(con dput(dentry); dentry = ERR_PTR(-EEXIST); } - if (IS_ERR(dentry)) + + if (IS_ERR(dentry)) { mutex_unlock(&parent->d_inode->i_mutex); + simple_release_fs(&tracefs_mount, &tracefs_mount_count); + } + return dentry; } Patches currently in stable-queue which might be from daniel@iogearbox.net are queue-4.3/tracefs-fix-refcount-imbalance-in-start_creating.patch