[PATCHv2] usb: f_rndis: Avoid to use ERROR macro if cdev can be null

From: oskar.andero
Date: Wed Mar 20 2013 - 09:02:55 EST

From: Truls Bengtsson <truls.bengtsson@xxxxxxxxxxxxxx>

The udc_irq service runs the isr_tr_complete_handler which in turn
"nukes" the endpoints, including a call to rndis_response_complete,
if appropriate. If the rndis_msg_parser fails here, an error will
be printed using a dev_err call (through the ERROR() macro).

However, if the usb cable was just disconnected the device (cdev)
might not be available and will be null. Since the dev_err macro will
dereference the cdev pointer we get a null pointer exception.

Reviewed-by: Radovan Lekanovic <radovan.lekanovic@xxxxxxxxxxxxxx>
Signed-off-by: Truls Bengtsson <truls.bengtsson@xxxxxxxxxxxxxx>
Signed-off-by: Oskar Andero <oskar.andero@xxxxxxxxxxxxxx>
Acked-by: Michal Nazarewicz <mina86@xxxxxxxxxx>
drivers/usb/gadget/f_rndis.c | 3 +--
1 files changed, 1 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/gadget/f_rndis.c b/drivers/usb/gadget/f_rndis.c
index 71beeb8..cc9c49c 100644
--- a/drivers/usb/gadget/f_rndis.c
+++ b/drivers/usb/gadget/f_rndis.c
@@ -447,14 +447,13 @@ static void rndis_response_complete(struct usb_ep *ep, struct usb_request *req)
static void rndis_command_complete(struct usb_ep *ep, struct usb_request *req)
struct f_rndis *rndis = req->context;
- struct usb_composite_dev *cdev = rndis->port.func.config->cdev;
int status;

// spin_lock(&dev->lock);
status = rndis_msg_parser(rndis->config, (u8 *) req->buf);
if (status < 0)
- ERROR(cdev, "RNDIS command error %d, %d/%d\n",
+ pr_err("RNDIS command error %d, %d/%d\n",
status, req->actual, req->length);
// spin_unlock(&dev->lock);

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