linux-kernel - [04/11] ecryptfs: initialize private persistent file before dereferencing pointer

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20100126191624.282924254@mini.kroah.org>
Date:	Tue, 26 Jan 2010 11:14:40 -0800
From:	Greg KH <gregkh@...e.de>
To:	linux-kernel@...r.kernel.org, stable@...nel.org
Cc:	stable-review@...nel.org, torvalds@...ux-foundation.org,
	akpm@...ux-foundation.org, alan@...rguk.ukuu.org.uk,
	Duckjin Kang <fromdj2k@...il.com>,
	Erez Zadok <ezk@...sunysb.edu>,
	Dustin Kirkland <kirkland@...onical.com>,
	Al Viro <viro@...iv.linux.org.uk>,
	Tyler Hicks <tyhicks@...ux.vnet.ibm.com>
Subject: [04/11] ecryptfs: initialize private persistent file before dereferencing pointer

2.6.27-stable review patch.  If anyone has any objections, please let us know.

------------------

From: Erez Zadok <ezk@...sunysb.edu>

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 <fromdj2k@...il.com>
Signed-off-by: Erez Zadok <ezk@...sunysb.edu>
Cc: Dustin Kirkland <kirkland@...onical.com>
Cc: Al Viro <viro@...iv.linux.org.uk>
Signed-off-by: Tyler Hicks <tyhicks@...ux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...e.de>

---
 fs/ecryptfs/file.c |   14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

--- a/fs/ecryptfs/file.c
+++ b/fs/ecryptfs/file.c
@@ -192,13 +192,6 @@ 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) {
@@ -209,6 +202,13 @@ 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)) {


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/