X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=fs%2Foverlayfs%2Finode.c;h=05ac9a95e88198f8ea4250ff77d32eba926efa57;hb=9042cdf4e1105ad5742db4e2dcf5355435476d5b;hp=4060ffde87225c81114d086c000773d4019255b5;hpb=0f7ff2dabbc95ed7a8019d142274f0c7e083577d;p=firefly-linux-kernel-4.4.55.git

diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index 4060ffde8722..05ac9a95e881 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -42,6 +42,19 @@ int ovl_setattr(struct dentry *dentry, struct iattr *attr)
 	int err;
 	struct dentry *upperdentry;
 
+	/*
+	 * Check for permissions before trying to copy-up.  This is redundant
+	 * since it will be rechecked later by ->setattr() on upper dentry.  But
+	 * without this, copy-up can be triggered by just about anybody.
+	 *
+	 * We don't initialize inode->size, which just means that
+	 * inode_newsize_ok() will always check against MAX_LFS_FILESIZE and not
+	 * check for a swapfile (which this won't be anyway).
+	 */
+	err = inode_change_ok(dentry->d_inode, attr);
+	if (err)
+		return err;
+
 	err = ovl_want_write(dentry);
 	if (err)
 		goto out;
@@ -52,6 +65,8 @@ int ovl_setattr(struct dentry *dentry, struct iattr *attr)
 
 		mutex_lock(&upperdentry->d_inode->i_mutex);
 		err = notify_change(upperdentry, attr, NULL);
+		if (!err)
+			ovl_copyattr(upperdentry->d_inode, dentry->d_inode);
 		mutex_unlock(&upperdentry->d_inode->i_mutex);
 	}
 	ovl_drop_write(dentry);