2.6.31-stable review patch. If anyone has any objections, please let us know. ------------------ From: Rafael J. Wysocki commit 497fb54f578efd2b479727bc88d5ef942c0a1e2d upstream. acpi_get_pci_dev() may be called for a non-PCI device, in which case it should return NULL. However, it assumes that every handle it finds in the ACPI CA name space, between given device handle and the PCI root bridge handle, corresponds to a PCI-to-PCI bridge with an existing secondary bus. For this reason, when it finds a struct pci_dev object corresponding to one of them, it doesn't check if its 'subordinate' field is a valid pointer. This obviously leads to a NULL pointer dereference if acpi_get_pci_dev() is called for a non-PCI device with a PCI parent which is not a bridge. To fix this issue make acpi_get_pci_dev() check if pdev->subordinate is not NULL for every device it finds on the path between the root bridge and the device it's supposed to get to and return NULL if the "target" device cannot be found. http://bugzilla.kernel.org/show_bug.cgi?id=14129 (worked in 2.6.30, regression in 2.6.31) Signed-off-by: Rafael J. Wysocki Reported-by: Danny Feng Reviewed-by: Alex Chiang Tested-by: chepioq Signed-off-by: Len Brown Cc: Chuck Ebbert Signed-off-by: Greg Kroah-Hartman --- drivers/acpi/pci_root.c | 11 +++++++++++ 1 file changed, 11 insertions(+) --- a/drivers/acpi/pci_root.c +++ b/drivers/acpi/pci_root.c @@ -400,6 +400,17 @@ struct pci_dev *acpi_get_pci_dev(acpi_ha pbus = pdev->subordinate; pci_dev_put(pdev); + + /* + * This function may be called for a non-PCI device that has a + * PCI parent (eg. a disk under a PCI SATA controller). In that + * case pdev->subordinate will be NULL for the parent. + */ + if (!pbus) { + dev_dbg(&pdev->dev, "Not a PCI-to-PCI bridge\n"); + pdev = NULL; + break; + } } out: list_for_each_entry_safe(node, tmp, &device_list, node) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/