diff mbox

[2/6] PCI: fix upstream P2P bridge checks when enabling OBFF and LTR

Message ID 20120621001643.4834.1430.stgit@bhelgaas.mtv.corp.google.com
State Accepted
Headers show

Commit Message

Bjorn Helgaas June 21, 2012, 12:16 a.m. UTC 
pci_enable_obff() and pci_enable_ltr() incorrectly check "dev->bus" instead
of "dev->bus->self" to determine whether the upstream device is a P2P
bridge or a host bridge.  For devices on the root bus, the upstream device
is a host bridge, "dev->bus != NULL" and "dev->bus->self == NULL", and we
panic with a null pointer dereference.

These functions should previously have panicked when called on devices
supporting OBFF or LTR, so they should be regarded as untested.

Found by Coverity (CID 143038 and CID 143039).

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
---
 drivers/pci/pci.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)


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diff mbox

Patch

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 8f4a5ea..b9e93cf 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -2108,7 +2108,7 @@  int pci_enable_obff(struct pci_dev *dev, enum pci_obff_signal_type type)
 		return -ENOTSUPP; /* no OBFF support at all */
 
 	/* Make sure the topology supports OBFF as well */
-	if (dev->bus) {
+	if (dev->bus->self) {
 		ret = pci_enable_obff(dev->bus->self, type);
 		if (ret)
 			return ret;
@@ -2215,7 +2215,7 @@  int pci_enable_ltr(struct pci_dev *dev)
 		return -EINVAL;
 
 	/* Enable upstream ports first */
-	if (dev->bus) {
+	if (dev->bus->self) {
 		ret = pci_enable_ltr(dev->bus->self);
 		if (ret)
 			return ret;