[coreboot-gerrit] Change in coreboot[master]: src/drivrs/usb: Avoid NULL pointer dereference

[John Zhao (Code Review)]

John Zhao has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/43449 )

Change subject: src/drivrs/usb: Avoid NULL pointer dereference
......................................................................

src/drivrs/usb: Avoid NULL pointer dereference

Coverity detects dereferencing pointers that might be "NULL" when
calling acpigen_write_scope and acpigen_write_device. Add sanity
check for both of scope and name to prevent NULL pointer dereference.

Found-by: Coverity CID 1430454
TEST=Built and boot up to kernel.

Signed-off-by: John Zhao 
Change-Id: I8ece3831bbd2641ceafbd71b9dc3db7e04a8eae4
---
M src/drivers/usb/pci_xhci/pci_xhci.c
1 file changed, 7 insertions(+), 2 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/49/43449/1

diff --git a/src/drivers/usb/pci_xhci/pci_xhci.c b/src/drivers/usb/pci_xhci/pci_xhci.c
index b787127..a375f07 100644
--- a/src/drivers/usb/pci_xhci/pci_xhci.c
+++ b/src/drivers/usb/pci_xhci/pci_xhci.c
@@ -187,11 +187,16 @@
 static void xhci_fill_ssdt(const struct device *dev)
 {
    int gpe;
+	const char *scope = acpi_device_scope(dev);
+	const char *name = acpi_device_name(dev);
+
+	if (!scope || !name)
+		return;

printk(BIOS_DEBUG, "xHCI SSDT generation\n");

-	acpigen_write_scope(acpi_device_scope(dev));
-	acpigen_write_device(acpi_device_name(dev));
+	acpigen_write_scope(scope);
+	acpigen_write_device(name);

acpigen_write_ADR_pci_device(dev);
    acpigen_write_name_string("_DDN", "xHC - Extensible Host Controller");