diff options
authorRafael J. Wysocki <>2009-10-13 01:01:57 +0200
committerLen Brown <>2009-10-13 01:14:53 -0400
commit497fb54f578efd2b479727bc88d5ef942c0a1e2d (patch)
parent374576a8b6f865022c0fd1ca62396889b23d66dd (diff)
ACPI / PCI: Fix NULL pointer dereference in acpi_get_pci_dev() (rev. 2)
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. (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 <>
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index 31122214e0ec..1af808171d46 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;
+ /*
+ * 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;
+ }
list_for_each_entry_safe(node, tmp, &device_list, node)