1 files changed, 26 insertions, 8 deletions

diff --git a/drivers/usb/gadget/legacy/inode.c b/drivers/usb/gadget/legacy/inode.c
index 78be94750232..51f9d96827b1 100644
--- a/drivers/usb/gadget/legacy/inode.c
+++ b/drivers/usb/gadget/legacy/inode.c
@@ -110,6 +110,8 @@ enum ep0_state {
 /* enough for the whole queue: most events invalidate others */
 #define	N_EVENT			5
 
+#define RBUF_SIZE		256
+
 struct dev_data {
 	spinlock_t			lock;
 	refcount_t			count;
@@ -144,7 +146,7 @@ struct dev_data {
 	struct dentry			*dentry;
 
 	/* except this scratch i/o buffer for ep0 */
-	u8				rbuf [256];
+	u8				rbuf[RBUF_SIZE];
 };
 
 static inline void get_dev (struct dev_data *data)
@@ -1240,7 +1242,7 @@ out:
 	return mask;
 }
 
-static long dev_ioctl (struct file *fd, unsigned code, unsigned long value)
+static long gadget_dev_ioctl (struct file *fd, unsigned code, unsigned long value)
 {
 	struct dev_data		*dev = fd->private_data;
 	struct usb_gadget	*gadget = dev->gadget;
@@ -1331,6 +1333,18 @@ gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
 	u16				w_value = le16_to_cpu(ctrl->wValue);
 	u16				w_length = le16_to_cpu(ctrl->wLength);
 
+	if (w_length > RBUF_SIZE) {
+		if (ctrl->bRequestType & USB_DIR_IN) {
+			/* Cast away the const, we are going to overwrite on purpose. */
+			__le16 *temp = (__le16 *)&ctrl->wLength;
+
+			*temp = cpu_to_le16(RBUF_SIZE);
+			w_length = RBUF_SIZE;
+		} else {
+			return value;
+		}
+	}
+
 	spin_lock (&dev->lock);
 	dev->setup_abort = 0;
 	if (dev->state == STATE_DEV_UNCONNECTED) {
@@ -1812,8 +1826,9 @@ dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 	spin_lock_irq (&dev->lock);
 	value = -EINVAL;
 	if (dev->buf) {
+		spin_unlock_irq(&dev->lock);
 		kfree(kbuf);
-		goto fail;
+		return value;
 	}
 	dev->buf = kbuf;
 
@@ -1860,8 +1875,8 @@ dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 
 	value = usb_gadget_probe_driver(&gadgetfs_driver);
 	if (value != 0) {
-		kfree (dev->buf);
-		dev->buf = NULL;
+		spin_lock_irq(&dev->lock);
+		goto fail;
 	} else {
 		/* at this point "good" hardware has for the first time
 		 * let the USB the host see us.  alternatively, if users
@@ -1878,6 +1893,9 @@ dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 	return value;
 
 fail:
+	dev->config = NULL;
+	dev->hs_config = NULL;
+	dev->dev = NULL;
 	spin_unlock_irq (&dev->lock);
 	pr_debug ("%s: %s fail %zd, %p\n", shortname, __func__, value, dev);
 	kfree (dev->buf);
@@ -1886,7 +1904,7 @@ fail:
 }
 
 static int
-dev_open (struct inode *inode, struct file *fd)
+gadget_dev_open (struct inode *inode, struct file *fd)
 {
 	struct dev_data		*dev = inode->i_private;
 	int			value = -EBUSY;
@@ -1906,12 +1924,12 @@ dev_open (struct inode *inode, struct file *fd)
 static const struct file_operations ep0_operations = {
 	.llseek =	no_llseek,
 
-	.open =		dev_open,
+	.open =		gadget_dev_open,
 	.read =		ep0_read,
 	.write =	dev_config,
 	.fasync =	ep0_fasync,
 	.poll =		ep0_poll,
-	.unlocked_ioctl = dev_ioctl,
+	.unlocked_ioctl = gadget_dev_ioctl,
 	.release =	dev_release,
 };