1 files changed, 8 insertions, 1 deletions

diff --git a/drivers/usb/misc/vstusb.c b/drivers/usb/misc/vstusb.c
index 874c81bb27b9..b787b25d4cc4 100644
--- a/drivers/usb/misc/vstusb.c
+++ b/drivers/usb/misc/vstusb.c
@@ -27,6 +27,7 @@
 #include <linux/slab.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
+#include <linux/smp_lock.h>
 #include <linux/uaccess.h>
 #include <linux/usb.h>
 
@@ -103,19 +104,23 @@ static int vstusb_open(struct inode *inode, struct file *file)
         struct vstusb_device *vstdev;
         struct usb_interface *interface;
 
+        lock_kernel();
         interface = usb_find_interface(&vstusb_driver, iminor(inode));
 
         if (!interface) {
                 printk(KERN_ERR KBUILD_MODNAME
                        ": %s - error, can't find device for minor %d\n",
                        __func__, iminor(inode));
+                unlock_kernel();
                 return -ENODEV;
         }
 
         vstdev = usb_get_intfdata(interface);
 
-        if (!vstdev)
+        if (!vstdev) {
+                unlock_kernel();
                 return -ENODEV;
+        }
 
         /* lock this device */
         mutex_lock(&vstdev->lock);
@@ -123,6 +128,7 @@ static int vstusb_open(struct inode *inode, struct file *file)
         /* can only open one time */
         if ((!vstdev->present) || (vstdev->isopen)) {
                 mutex_unlock(&vstdev->lock);
+                unlock_kernel();
                 return -EBUSY;
         }
 
@@ -137,6 +143,7 @@ static int vstusb_open(struct inode *inode, struct file *file)
         dev_dbg(&vstdev->usb_dev->dev, "%s: opened\n", __func__);
 
         mutex_unlock(&vstdev->lock);
+        unlock_kernel();
 
         return 0;
 }