From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757745Ab0CaAaW (ORCPT ); Tue, 30 Mar 2010 20:30:22 -0400 Received: from kroah.org ([198.145.64.141]:48864 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755458Ab0C3XMN (ORCPT ); Tue, 30 Mar 2010 19:12:13 -0400 X-Mailbox-Line: From linux@linux.site Tue Mar 30 15:58:23 2010 Message-Id: <20100330225823.278033735@linux.site> User-Agent: quilt/0.47-14.9 Date: Tue, 30 Mar 2010 15:57:26 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Duckjin Kang , Erez Zadok , Dustin Kirkland , Al Viro , Tyler Hicks , Greg Kroah-Hartman Subject: [24/89] ecryptfs: initialize private persistent file before dereferencing pointer In-Reply-To: <20100330230520.GA28779@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.31-stable review patch. If anyone has any objections, please let us know. ------------------ From: Erez Zadok commit e27759d7a333d1f25d628c4f7caf845c51be51c2 upstream. Ecryptfs_open dereferences a pointer to the private lower file (the one stored in the ecryptfs inode), without checking if the pointer is NULL. Right afterward, it initializes that pointer if it is NULL. Swap order of statements to first initialize. Bug discovered by Duckjin Kang. Signed-off-by: Duckjin Kang Signed-off-by: Erez Zadok Cc: Dustin Kirkland Cc: Al Viro Signed-off-by: Tyler Hicks Signed-off-by: Greg Kroah-Hartman --- fs/ecryptfs/file.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) --- a/fs/ecryptfs/file.c +++ b/fs/ecryptfs/file.c @@ -191,13 +191,6 @@ static int ecryptfs_open(struct inode *i | ECRYPTFS_ENCRYPTED); } mutex_unlock(&crypt_stat->cs_mutex); - if ((ecryptfs_inode_to_private(inode)->lower_file->f_flags & O_RDONLY) - && !(file->f_flags & O_RDONLY)) { - rc = -EPERM; - printk(KERN_WARNING "%s: Lower persistent file is RO; eCryptfs " - "file must hence be opened RO\n", __func__); - goto out; - } if (!ecryptfs_inode_to_private(inode)->lower_file) { rc = ecryptfs_init_persistent_file(ecryptfs_dentry); if (rc) { @@ -208,6 +201,13 @@ static int ecryptfs_open(struct inode *i goto out; } } + if ((ecryptfs_inode_to_private(inode)->lower_file->f_flags & O_RDONLY) + && !(file->f_flags & O_RDONLY)) { + rc = -EPERM; + printk(KERN_WARNING "%s: Lower persistent file is RO; eCryptfs " + "file must hence be opened RO\n", __func__); + goto out; + } ecryptfs_set_file_lower( file, ecryptfs_inode_to_private(inode)->lower_file); if (S_ISDIR(ecryptfs_dentry->d_inode->i_mode)) {