From 5307f6d5fb12fd01f9f321bc4a8fd77e74858647 Mon Sep 17 00:00:00 2001 From: Shyam Iyer Date: Thu, 8 Sep 2011 16:41:17 -0500 Subject: [PATCH] Fix pointer dereference before call to pcie_bus_configure_settings Commit b03e7495a862 ("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 Signed-off-by: Shyam Iyer Signed-off-by: Jon Mason Acked-by: Jesse Barnes Signed-off-by: Linus Torvalds --- arch/x86/pci/acpi.c | 9 +++++++-- drivers/pci/hotplug/pcihp_slot.c | 4 +++- drivers/pci/probe.c | 3 --- 3 files changed, 10 insertions(+), 6 deletions(-) diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c index c95330267f08..039d91315bc5 100644 --- a/arch/x86/pci/acpi.c +++ b/arch/x86/pci/acpi.c @@ -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) diff --git a/drivers/pci/hotplug/pcihp_slot.c b/drivers/pci/hotplug/pcihp_slot.c index 753b21aaea61..3ffd9c1acc0a 100644 --- a/drivers/pci/hotplug/pcihp_slot.c +++ b/drivers/pci/hotplug/pcihp_slot.c @@ -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); diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 8473727b29fa..0820fc1544e8 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -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; -- 2.39.5