From: Troy Moure <twmoure@xxxxxxxxx> ref: http://thread.gmane.org/gmane.linux.kernel/857228/focus=857468 When the ACPI video driver initializes, it does a namespace walk looking for for supported devices. When we find an appropriate handle, we walk up the ACPI tree looking for a PCI root bus, and then walk back down the PCI bus, assuming that every device inbetween is a P2P bridge. This assumption is not correct, and is reported broken on at least: Dell Latitude E6400 ThinkPad X61 Dell XPS M1330 Add a NULL deref check to prevent boot panics. Reported-by: Alessandro Suardi <alessandro.suardi@xxxxxxxxx> Signed-off-by: Troy Moure <twmoure@xxxxxxxxx> Signed-off-by: Alex Chiang <achiang@xxxxxx> Signed-off-by: Len Brown <len.brown@xxxxxxxxx> --- drivers/acpi/pci_root.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c index 8a5bf3b..55b5b90 100644 --- a/drivers/acpi/pci_root.c +++ b/drivers/acpi/pci_root.c @@ -395,7 +395,7 @@ struct pci_dev *acpi_get_pci_dev(acpi_handle handle) fn = adr & 0xffff; pdev = pci_get_slot(pbus, PCI_DEVFN(dev, fn)); - if (hnd == handle) + if (!pdev || hnd == handle) break; pbus = pdev->subordinate; -- 1.6.0.6 -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
