[PATCH] Fix NULL ptr dereference in pci_bus_assign_domain_nr() on ARM
From: helgaas@kernel.org (Bjorn Helgaas)
Date: 2016-03-03 17:35:28
Also in:
linux-pci, lkml
Hi Krzysztof, On Tue, Mar 01, 2016 at 07:07:18AM +0100, Krzysztof Ha?asa wrote:
Many ARM platforms use a wrapper:
/*
* Compatibility wrapper for older platforms that do not care about
* passing the parent device.
*/
static inline void pci_common_init(struct hw_pci *hw)
{
pci_common_init_dev(NULL, hw);
}
which means that pci_bus_assign_domain_nr() can be called without
a parent. This patch fixes the NULL pointer dereference.What exactly is the impact of this? Does this fix need to be in v4.5? It sounds like it should be, but I need a little more detailed justification, e.g., "platforms X, Y, Z don't boot at all without this change."
quoted hunk ↗ jump to hunk
Signed-off-by: Krzysztof Ha?asa <khalasa@piap.pl> Cc: stable at vger.kernel.orgdiff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 602eb42..f89db3a 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c@@ -4772,8 +4772,10 @@ int pci_get_new_domain_nr(void) void pci_bus_assign_domain_nr(struct pci_bus *bus, struct device *parent) { static int use_dt_domains = -1; - int domain = of_get_pci_domain_nr(parent->of_node); + int domain = -1; + if (parent) + domain = of_get_pci_domain_nr(parent->of_node); /* * Check DT domain and use_dt_domains values. *-- Krzysztof Halasa Industrial Research Institute for Automation and Measurements PIAP Al. Jerozolimskie 202, 02-486 Warsaw, Poland