[PATCH] USB: usbcore: usb_set_configuration oops (NULL ptr dereference)
When trying to deconfigure a device via usb_set_configuration(dev, 0),
2.6.16-rc kernels after 55c527187c9d78f840b284d596a0b298bc1493af oops
with "Unable to handle NULL pointer dereference at...". This is due to
an unchecked dereference of cp in the power budget part.
Signed-off-by: Horst Schirmeier <horst@schirmeier.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
index 2f6009b..08fb20f 100644
--- a/drivers/usb/core/message.c
+++ b/drivers/usb/core/message.c
@@ -1388,11 +1388,13 @@
if (dev->state != USB_STATE_ADDRESS)
usb_disable_device (dev, 1); // Skip ep0
- i = dev->bus_mA - cp->desc.bMaxPower * 2;
- if (i < 0)
- dev_warn(&dev->dev, "new config #%d exceeds power "
- "limit by %dmA\n",
- configuration, -i);
+ if (cp) {
+ i = dev->bus_mA - cp->desc.bMaxPower * 2;
+ if (i < 0)
+ dev_warn(&dev->dev, "new config #%d exceeds power "
+ "limit by %dmA\n",
+ configuration, -i);
+ }
if ((ret = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
USB_REQ_SET_CONFIGURATION, 0, configuration, 0,