From 412af97838828bc6d035a1902c8974f944663da6 Mon Sep 17 00:00:00 2001 From: Troy Moure Date: Thu, 25 Jun 2009 17:05:35 -0600 Subject: [PATCH] ACPI: video: prevent NULL deref in acpi_get_pci_dev() 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 Signed-off-by: Troy Moure Signed-off-by: Alex Chiang Signed-off-by: Len Brown --- drivers/acpi/pci_root.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c index 8a5bf3b356fa..55b5b90c2a44 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; -- 2.20.1