From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Tue, 16 Sep 2014 15:20:48 -0600 From: Bjorn Helgaas To: Andreas Noever Cc: linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org Subject: Re: [PATCH] PCI: Prevent NULL dereference during pciehp probe Message-ID: <20140916212048.GA5050@google.com> References: <1402347812-8059-1-git-send-email-andreas.noever@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1402347812-8059-1-git-send-email-andreas.noever@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: On Mon, Jun 09, 2014 at 11:03:32PM +0200, Andreas Noever wrote: > pciehp assumes that dev->subordinate exists. But we do not assign a bus > if we run out of bus numbers during enumeration. This leads to a NULL > dereference in init_slot (and other places). > > Change pciehp_probe to return -ENODEV when no subordinate bus is > present. > > Signed-off-by: Andreas Noever Applied to pci/hotplug for v3.18, thanks! > --- > drivers/pci/hotplug/pciehp_core.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/drivers/pci/hotplug/pciehp_core.c b/drivers/pci/hotplug/pciehp_core.c > index 0e0a2ff..e5abcaf 100644 > --- a/drivers/pci/hotplug/pciehp_core.c > +++ b/drivers/pci/hotplug/pciehp_core.c > @@ -255,6 +255,13 @@ static int pciehp_probe(struct pcie_device *dev) > else if (pciehp_acpi_slot_detection_check(dev->port)) > goto err_out_none; > > + if (!dev->port->subordinate) { > + /* Can happen if we run out of bus numbers during probe */ > + dev_err(&dev->device, > + "Hotplug bridge without secondary bus, ignoring\n"); > + goto err_out_none; > + } > + > ctrl = pcie_init(dev); > if (!ctrl) { > dev_err(&dev->device, "Controller initialization failed\n"); > -- > 2.0.0 >