[PATCH 4.19 007/110] usb: dwc3: Fix NULL pointer exception in dwc3_pci_remove()

[Greg Kroah-Hartman]

4.19-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx>

commit 7b412b04a0c7000293008231ce8413056abb1982 upstream.

In dwc3_pci_quirks() function, gpiod lookup table is only registered for
baytrail SOC. But in dwc3_pci_remove(), we try to unregistered it
without any checks. This leads to NULL pointer de-reference exception in
gpiod_remove_lookup_table() when unloading the module for non baytrail
SOCs. This patch fixes this issue.

Fixes: 5741022cbdf3 ("usb: dwc3: pci: Add GPIO lookup table on platforms
without ACPI GPIO resources")
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx>
Reviewed-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
Signed-off-by: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/usb/dwc3/dwc3-pci.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/usb/dwc3/dwc3-pci.c
+++ b/drivers/usb/dwc3/dwc3-pci.c
@@ -283,8 +283,10 @@ err:
 static void dwc3_pci_remove(struct pci_dev *pci)
 {
 	struct dwc3_pci		*dwc = pci_get_drvdata(pci);
+	struct pci_dev		*pdev = dwc->pci;
 
-	gpiod_remove_lookup_table(&platform_bytcr_gpios);
+	if (pdev->device == PCI_DEVICE_ID_INTEL_BYT)
+		gpiod_remove_lookup_table(&platform_bytcr_gpios);
 #ifdef CONFIG_PM
 	cancel_work_sync(&dwc->wakeup_work);
 #endif