Fix pointer dereference before call to pcie_bus_configure_settings

Commit b03e7495a8 ("PCI: Set PCI-E Max Payload Size on fabric")
introduced a potential NULL pointer dereference in calls to
pcie_bus_configure_settings due to attempts to access pci_bus self
variables when the self pointer is NULL.

To correct this, verify that the self pointer in pci_bus is non-NULL
before dereferencing it.

Reported-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Shyam Iyer <shyam_iyer@dell.com>
Signed-off-by: Jon Mason <mason@myri.com>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Shyam Iyer 2011-09-08 16:41:17 -05:00 committed by Linus Torvalds
parent a6a5ed0dd3
commit 5307f6d5fb
3 changed files with 10 additions and 6 deletions

View file

@ -365,8 +365,13 @@ struct pci_bus * __devinit pci_acpi_scan_root(struct acpi_pci_root *root)
*/
if (bus) {
struct pci_bus *child;
list_for_each_entry(child, &bus->children, node)
pcie_bus_configure_settings(child, child->self->pcie_mpss);
list_for_each_entry(child, &bus->children, node) {
struct pci_dev *self = child->self;
if (!self)
continue;
pcie_bus_configure_settings(child, self->pcie_mpss);
}
}
if (!bus)

View file

@ -169,7 +169,9 @@ void pci_configure_slot(struct pci_dev *dev)
(dev->class >> 8) == PCI_CLASS_BRIDGE_PCI)))
return;
pcie_bus_configure_settings(dev->bus, dev->bus->self->pcie_mpss);
if (dev->bus && dev->bus->self)
pcie_bus_configure_settings(dev->bus,
dev->bus->self->pcie_mpss);
memset(&hpp, 0, sizeof(hpp));
ret = pci_get_hp_params(dev, &hpp);

View file

@ -1456,9 +1456,6 @@ void pcie_bus_configure_settings(struct pci_bus *bus, u8 mpss)
{
u8 smpss = mpss;
if (!bus->self)
return;
if (!pci_is_pcie(bus->self))
return;