2 files changed, 46 insertions, 17 deletions

diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c
index e809e9d..696e851 100644
--- a/drivers/tty/pty.c
+++ b/drivers/tty/pty.c
@@ -670,12 +670,18 @@ static int ptmx_open(struct inode *inode, struct file *filp)
 
 	nonseekable_open(inode, filp);
 
+	retval = tty_alloc_file(filp);
+	if (retval)
+		return retval;
+
 	/* find a device that is not in use. */
 	tty_lock();
 	index = devpts_new_index(inode);
 	tty_unlock();
-	if (index < 0)
-		return index;
+	if (index < 0) {
+		retval = index;
+		goto err_file;
+	}
 
 	mutex_lock(&tty_mutex);
 	tty_lock();
@@ -689,9 +695,7 @@ static int ptmx_open(struct inode *inode, struct file *filp)
 
 	set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */
 
-	retval = tty_add_file(tty, filp);
-	if (retval)
-		goto out;
+	tty_add_file(tty, filp);
 
 	retval = devpts_pty_new(inode, tty->link);
 	if (retval)
@@ -710,6 +714,8 @@ out2:
 out:
 	devpts_kill_index(inode, index);
 	tty_unlock();
+err_file:
+	tty_free_file(filp);
 	return retval;
 }
 
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index e9495ed..b44aef0 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -193,8 +193,7 @@ static inline struct tty_struct *file_tty(struct file *file)
 	return ((struct tty_file_private *)file->private_data)->tty;
 }
 
-/* Associate a new file with the tty structure */
-int tty_add_file(struct tty_struct *tty, struct file *file)
+int tty_alloc_file(struct file *file)
 {
 	struct tty_file_private *priv;
 
@@ -202,15 +201,36 @@ int tty_add_file(struct tty_struct *tty, struct file *file)
 	if (!priv)
 		return -ENOMEM;
 
+	file->private_data = priv;
+
+	return 0;
+}
+
+/* Associate a new file with the tty structure */
+void tty_add_file(struct tty_struct *tty, struct file *file)
+{
+	struct tty_file_private *priv = file->private_data;
+
 	priv->tty = tty;
 	priv->file = file;
-	file->private_data = priv;
 
 	spin_lock(&tty_files_lock);
 	list_add(&priv->list, &tty->tty_files);
 	spin_unlock(&tty_files_lock);
+}
 
-	return 0;
+/**
+ * tty_free_file - free file->private_data
+ *
+ * This shall be used only for fail path handling when tty_add_file was not
+ * called yet.
+ */
+void tty_free_file(struct file *file)
+{
+	struct tty_file_private *priv = file->private_data;
+
+	file->private_data = NULL;
+	kfree(priv);
 }
 
 /* Delete file from its tty */
@@ -221,8 +241,7 @@ void tty_del_file(struct file *file)
 	spin_lock(&tty_files_lock);
 	list_del(&priv->list);
 	spin_unlock(&tty_files_lock);
-	file->private_data = NULL;
-	kfree(priv);
+	tty_free_file(file);
 }
 
 
@@ -1811,6 +1830,10 @@ static int tty_open(struct inode *inode, struct file *filp)
 	nonseekable_open(inode, filp);
 
 retry_open:
+	retval = tty_alloc_file(filp);
+	if (retval)
+		return -ENOMEM;
+
 	noctty = filp->f_flags & O_NOCTTY;
 	index  = -1;
 	retval = 0;
@@ -1823,6 +1846,7 @@ retry_open:
 		if (!tty) {
 			tty_unlock();
 			mutex_unlock(&tty_mutex);
+			tty_free_file(filp);
 			return -ENXIO;
 		}
 		driver = tty_driver_kref_get(tty->driver);
@@ -1855,6 +1879,7 @@ retry_open:
 		}
 		tty_unlock();
 		mutex_unlock(&tty_mutex);
+		tty_free_file(filp);
 		return -ENODEV;
 	}
 
@@ -1862,6 +1887,7 @@ retry_open:
 	if (!driver) {
 		tty_unlock();
 		mutex_unlock(&tty_mutex);
+		tty_free_file(filp);
 		return -ENODEV;
 	}
 got_driver:
@@ -1873,6 +1899,7 @@ got_driver:
 			tty_unlock();
 			mutex_unlock(&tty_mutex);
 			tty_driver_kref_put(driver);
+			tty_free_file(filp);
 			return PTR_ERR(tty);
 		}
 	}
@@ -1888,15 +1915,11 @@ got_driver:
 	tty_driver_kref_put(driver);
 	if (IS_ERR(tty)) {
 		tty_unlock();
+		tty_free_file(filp);
 		return PTR_ERR(tty);
 	}
 
-	retval = tty_add_file(tty, filp);
-	if (retval) {
-		tty_unlock();
-		tty_release(inode, filp);
-		return retval;
-	}
+	tty_add_file(tty, filp);
 
 	check_tty_count(tty, "tty_open");
 	if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&