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

From: Greg Kroah-Hartman
Date: Thu Nov 29 2018 - 09:29:04 EST

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