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 <[email protected]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
blinkosm · Jul 19, 2007 · 64ee480 · 64ee480
1 parent 39ef01e
commit 64ee480
Showing 1 changed file with 3 additions and 2 deletions.
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
@@ -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;