From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tyler Hicks Subject: [PATCH] eCryptfs: file->private_data is always valid Date: Wed, 13 Nov 2013 10:54:03 -0800 Message-ID: <1384368843-10072-1-git-send-email-tyhicks@canonical.com> References: <20131112103013.GB10651@elgon.mountain> Return-path: Received: from youngberry.canonical.com ([91.189.89.112]:41655 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756640Ab3KMSyK (ORCPT ); Wed, 13 Nov 2013 13:54:10 -0500 In-Reply-To: <20131112103013.GB10651@elgon.mountain> Sender: ecryptfs-owner@vger.kernel.org List-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: ecryptfs@vger.kernel.org Cc: Dan Carpenter , Al Viro When accessing the lower_file pointer located in private_data of eCryptfs files, there is no need to check to see if the private_data pointer has been initialized to a non-NULL value. The file->private_data and file->private_data->lower_file pointers are always initialized to non-NULL values in ecryptfs_open(). This change quiets a Smatch warning: CHECK /var/scm/kernel/linux/fs/ecryptfs/file.c fs/ecryptfs/file.c:321 ecryptfs_unlocked_ioctl() error: potential NULL dereference 'lower_file'. fs/ecryptfs/file.c:335 ecryptfs_compat_ioctl() error: potential NULL dereference 'lower_file'. Signed-off-by: Tyler Hicks Reported-by: Dan Carpenter Cc: Al Viro --- Thanks, Dan! You're right that the "if (ecryptfs_file_to_private(file))" check is not needed. I'll include this patch in an upcoming pull request. Tyler fs/ecryptfs/file.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c index 2229a74..b1eaa7a 100644 --- a/fs/ecryptfs/file.c +++ b/fs/ecryptfs/file.c @@ -313,11 +313,9 @@ static int ecryptfs_fasync(int fd, struct file *file, int flag) static long ecryptfs_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { - struct file *lower_file = NULL; + struct file *lower_file = ecryptfs_file_to_lower(file); long rc = -ENOTTY; - if (ecryptfs_file_to_private(file)) - lower_file = ecryptfs_file_to_lower(file); if (lower_file->f_op->unlocked_ioctl) rc = lower_file->f_op->unlocked_ioctl(lower_file, cmd, arg); return rc; @@ -327,11 +325,9 @@ ecryptfs_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg) static long ecryptfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { - struct file *lower_file = NULL; + struct file *lower_file = ecryptfs_file_to_lower(file); long rc = -ENOIOCTLCMD; - if (ecryptfs_file_to_private(file)) - lower_file = ecryptfs_file_to_lower(file); if (lower_file->f_op && lower_file->f_op->compat_ioctl) rc = lower_file->f_op->compat_ioctl(lower_file, cmd, arg); return rc; -- 1.8.3.2