Re: [Xen-devel] [PATCH] xen: avoid NULL pointer dereference in dom0 on large machines

From: David Vrabel
Date: Fri Mar 06 2015 - 08:18:39 EST


On 26/02/15 05:52, Juergen Gross wrote:
> Using the pvops kernel a NULL pointer dereference was detected on a
> large machine (144 processors) when booting as dom0 in
> evtchn_fifo_unmask() during assignment of a pirq.
>
> The event channel in question was the first to need a new entry in
> event_array[] in events_fifo.c. Unfortunately xen_irq_info_pirq_setup()
> is called with evtchn being 0 for a new pirq and the real event channel
> number is assigned to the pirq only during __startup_pirq().
>
> It is mandatory to call xen_evtchn_port_setup() after assigning the
> event channel number to the pirq to make sure all memory needed for the
> event channel is allocated.

Applied to stable/for-linus-4.0 and tagged for stable, thanks.

David
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