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. Fixes http://bugzilla.kernel.org/show_bug.cgi?id=14129, which is a regression from 2.6.30. Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx> --- Jesse, Len, This is a replacement for the original $subject patch (now in the Len's tree as commit 5988eaded02e3cca2702f46efc255143468255bd). The code was correct, but the comment and the changelog were not. Please use the one below instead. Thanks, Rafael --- drivers/acpi/pci_root.c | 11 +++++++++++ 1 file changed, 11 insertions(+) Index: linux-2.6/drivers/acpi/pci_root.c =================================================================== --- linux-2.6.orig/drivers/acpi/pci_root.c +++ linux-2.6/drivers/acpi/pci_root.c @@ -389,6 +389,17 @@ 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-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
