Re: [PATCH] Fix NULL ptr dereference in pci_bus_assign_domain_nr() on ARM

Bjorn Helgaas
2016-03-04T16:27:45Z

On Fri, Mar 04, 2016 at 07:13:49AM +0100, Krzysztof Hałasa wrote:
> Hi Bjorn,
>
> Bjorn Helgaas <helgaas@kernel.org> writes:
>
> > On Tue, Mar 01, 2016 at 07:07:18AM +0100, Krzysztof Hałasa 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."
>
> At least CNS3xxx doesn't boot. I haven't verified a couple of others,
> but they may be broken as well.

Good, thanks. Also (I should have asked this before), please include a
"Fixes:" line so we know exactly when this broke and what stable kernels
need the fix.

Bjorn