usb: usbip: set buffer pointers to NULL after free

The usbip stack dynamically allocates the transfer_buffer and
setup_packet of each urb that got generated by the tcp to usb stub code.
As these pointers are always used only once we will set them to NULL
after use. This is done likewise to the free_urb code in vudc_dev.c.
This patch fixes double kfree situations where the usbip remote side
added the URB_FREE_BUFFER.

Cc: stable@vger.kernel.org
Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Acked-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/usbip/stub_main.c b/drivers/usb/usbip/stub_main.c
index 44ab43fc4fcc71c8f7732e5c74120ae278b0b89f..af10f7b131a4920ec96190b954d43996a7af9e4d 100644 (file)
--- a/drivers/usb/usbip/stub_main.c
+++ b/drivers/usb/usbip/stub_main.c
@@ -262,7 +262,11 @@ void stub_device_cleanup_urbs(struct stub_device *sdev)
                kmem_cache_free(stub_priv_cache, priv);
 
                kfree(urb->transfer_buffer);
+               urb->transfer_buffer = NULL;
+
                kfree(urb->setup_packet);
+               urb->setup_packet = NULL;
+
                usb_free_urb(urb);
        }
 }

diff --git a/drivers/usb/usbip/stub_tx.c b/drivers/usb/usbip/stub_tx.c
index 6b1e8c3f0e4b28815dcbb0539f2b7a24d023100d..be50cef645d8aadb04d49314d86ed7947c182572 100644 (file)
--- a/drivers/usb/usbip/stub_tx.c
+++ b/drivers/usb/usbip/stub_tx.c
@@ -28,7 +28,11 @@ static void stub_free_priv_and_urb(struct stub_priv *priv)
        struct urb *urb = priv->urb;
 
        kfree(urb->setup_packet);
+       urb->setup_packet = NULL;
+
        kfree(urb->transfer_buffer);
+       urb->transfer_buffer = NULL;
+
        list_del(&priv->list);
        kmem_cache_free(stub_priv_cache, priv);
        usb_free_urb(urb);