can: c_can_pci: fix null-pointer-deref in c_can_start() - set device pointer

commit c97c52be upstream.

The priv->device pointer for c_can_pci is never set, but it is used
without a NULL check in c_can_start(). Setting it in c_can_pci_probe()
like c_can_plat_probe() prevents c_can_pci.ko from crashing, with and
without CONFIG_PM.

This might also cause the pm_runtime_*() functions in c_can.c to
actually be executed for c_can_pci devices - they are the only other
place where priv->device is used, but they all contain a null check.
Signed-off-by: Einar Jón <tolvupostur@gmail.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

drivers/net/can/c_can/c_can_pci.c

@@ -161,6 +161,7 @@ static int c_can_pci_probe(struct pci_dev *pdev,
 
 	dev->irq = pdev->irq;
 	priv->base = addr;
+	priv->device = &pdev->dev;
 
 	if (!c_can_pci_data->freq) {
 		dev_err(&pdev->dev, "no clock frequency defined\n");