From: Rafael J. Wysocki <rjw@xxxxxxx> 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 <rjw@xxxxxxx> Reported-by: Danny Feng <dfeng@xxxxxxxxxx> Reviewed-by: Alex Chiang <achiang@xxxxxx> Tested-by: chepioq <chepioq@xxxxxxxxx> Signed-off-by: Len Brown <len.brown@xxxxxxxxx> --- drivers/acpi/pci_root.c | 11 +++++++++++ 1 files changed, 11 insertions(+), 0 deletions(-) diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c index 3112221..1af8081 100644 --- a/drivers/acpi/pci_root.c +++ b/drivers/acpi/pci_root.c @@ -389,6 +389,17 @@ struct pci_dev *acpi_get_pci_dev(acpi_handle handle) 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) -- 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
