usb: gadget: functionfs: fix missing access_ok checks

use safe copy_*_user instead of unsafe __copy_*_user
functions when accessing userland memory.

Signed-off-by: Daniel Walter <dwalter@sigma-star.at>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/gadget/function/f_fs.c

@@ -423,7 +423,7 @@ static ssize_t __ffs_ep0_read_events(struct ffs_data *ffs, char __user *buf,
 	spin_unlock_irq(&ffs->ev.waitq.lock);
 	mutex_unlock(&ffs->mutex);
 
-	return unlikely(__copy_to_user(buf, events, size)) ? -EFAULT : size;
+	return unlikely(copy_to_user(buf, events, size)) ? -EFAULT : size;
 }
 
 static ssize_t ffs_ep0_read(struct file *file, char __user *buf,
@@ -513,7 +513,7 @@ static ssize_t ffs_ep0_read(struct file *file, char __user *buf,
 
 		/* unlocks spinlock */
 		ret = __ffs_ep0_queue_wait(ffs, data, len);
-		if (likely(ret > 0) && unlikely(__copy_to_user(buf, data, len)))
+		if (likely(ret > 0) && unlikely(copy_to_user(buf, data, len)))
 			ret = -EFAULT;
 		goto done_mutex;
 
@@ -3493,7 +3493,7 @@ static char *ffs_prepare_buffer(const char __user *buf, size_t len)
 	if (unlikely(!data))
 		return ERR_PTR(-ENOMEM);
 
-	if (unlikely(__copy_from_user(data, buf, len))) {
+	if (unlikely(copy_from_user(data, buf, len))) {
 		kfree(data);
 		return ERR_PTR(-EFAULT);
 	}