1 files changed, 12 insertions, 8 deletions

diff --git a/drivers/usb/misc/ldusb.c b/drivers/usb/misc/ldusb.c
index fa5cf349ae19..cd92ae1231bc 100644
--- a/drivers/usb/misc/ldusb.c
+++ b/drivers/usb/misc/ldusb.c
@@ -383,10 +383,7 @@ static int ld_usb_release(struct inode *inode, struct file *file)
 		goto exit;
 	}
 
-	if (mutex_lock_interruptible(&dev->mutex)) {
-		retval = -ERESTARTSYS;
-		goto exit;
-	}
+	mutex_lock(&dev->mutex);
 
 	if (dev->open_count != 1) {
 		retval = -ENODEV;
@@ -470,7 +467,7 @@ static ssize_t ld_usb_read(struct file *file, char __user *buffer, size_t count,
 
 	/* wait for data */
 	spin_lock_irq(&dev->rbsl);
-	if (dev->ring_head == dev->ring_tail) {
+	while (dev->ring_head == dev->ring_tail) {
 		dev->interrupt_in_done = 0;
 		spin_unlock_irq(&dev->rbsl);
 		if (file->f_flags & O_NONBLOCK) {
@@ -480,12 +477,17 @@ static ssize_t ld_usb_read(struct file *file, char __user *buffer, size_t count,
 		retval = wait_event_interruptible(dev->read_wait, dev->interrupt_in_done);
 		if (retval < 0)
 			goto unlock_exit;
-	} else {
-		spin_unlock_irq(&dev->rbsl);
+
+		spin_lock_irq(&dev->rbsl);
 	}
+	spin_unlock_irq(&dev->rbsl);
 
 	/* actual_buffer contains actual_length + interrupt_in_buffer */
 	actual_buffer = (size_t *)(dev->ring_buffer + dev->ring_tail * (sizeof(size_t)+dev->interrupt_in_endpoint_size));
+	if (*actual_buffer > dev->interrupt_in_endpoint_size) {
+		retval = -EIO;
+		goto unlock_exit;
+	}
 	bytes_to_read = min(count, *actual_buffer);
 	if (bytes_to_read < *actual_buffer)
 		dev_warn(&dev->intf->dev, "Read buffer overflow, %zd bytes dropped\n",
@@ -696,7 +698,9 @@ static int ld_usb_probe(struct usb_interface *intf, const struct usb_device_id *
 		dev_warn(&intf->dev, "Interrupt out endpoint not found (using control endpoint instead)\n");
 
 	dev->interrupt_in_endpoint_size = usb_endpoint_maxp(dev->interrupt_in_endpoint);
-	dev->ring_buffer = kmalloc(ring_buffer_size*(sizeof(size_t)+dev->interrupt_in_endpoint_size), GFP_KERNEL);
+	dev->ring_buffer = kcalloc(ring_buffer_size,
+			sizeof(size_t) + dev->interrupt_in_endpoint_size,
+			GFP_KERNEL);
 	if (!dev->ring_buffer)
 		goto error;
 	dev->interrupt_in_buffer = kmalloc(dev->interrupt_in_endpoint_size, GFP_KERNEL);