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. This patch was already included in Linus' tree. Signed-off-by: Horst Schirmeier Acked-by: Alan Stern Signed-off-by: Greg Kroah-Hartman Signed-off-by: Adrian Bunk --- drivers/usb/core/message.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) --- linux-2.6.16.1.orig/drivers/usb/core/message.c +++ linux-2.6.16.1/drivers/usb/core/message.c @@ -1388,11 +1388,13 @@ free_interfaces: 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, --