eCryptfs: ecryptfs_setattr() bugfix

There is another bug recently introduced into the ecryptfs_setattr()
function in 2.6.22.  eCryptfs will attempt to treat special files like
regular eCryptfs files on chmod, chown, and so forth.  This leads to a NULL
pointer dereference.  This patch validates that the file is a regular file
before proceeding with operations related to the inode's crypt_stat.

Thanks to Ryusuke Konishi for finding this bug and suggesting the fix.

Signed-off-by: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Michael Halcrow 2007-07-19 01:47:54 -07:00 committed by Linus Torvalds
parent 39ef01e00d
commit 64ee4808a7

View File

@ -902,8 +902,9 @@ static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
mutex_lock(&crypt_stat->cs_mutex);
if (S_ISDIR(dentry->d_inode->i_mode))
crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
else if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)
|| !(crypt_stat->flags & ECRYPTFS_KEY_VALID)) {
else if (S_ISREG(dentry->d_inode->i_mode)
&& (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)
|| !(crypt_stat->flags & ECRYPTFS_KEY_VALID))) {
struct vfsmount *lower_mnt;
struct file *lower_file = NULL;
struct ecryptfs_mount_crypt_stat *mount_crypt_stat;