This is a note to let you know that I've just added the patch titled
xen/events: avoid NULL pointer dereference in dom0 on large machines
to the 3.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
xen-events-avoid-null-pointer-dereference-in-dom0-on-large-machines.patch
and it can be found in the queue-3.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From 85e40b0539b24518c8bdf63e2605c8522377d00f Mon Sep 17 00:00:00 2001
From: Juergen Gross <[email protected]>
Date: Thu, 26 Feb 2015 06:52:05 +0100
Subject: xen/events: avoid NULL pointer dereference in dom0 on large machines
From: Juergen Gross <[email protected]>
commit 85e40b0539b24518c8bdf63e2605c8522377d00f upstream.
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.
Signed-off-by: Juergen Gross <[email protected]>
Signed-off-by: David Vrabel <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/xen/events/events_base.c | 18 ++++++++++++------
1 file changed, 12 insertions(+), 6 deletions(-)
--- a/drivers/xen/events/events_base.c
+++ b/drivers/xen/events/events_base.c
@@ -547,20 +547,26 @@ static unsigned int __startup_pirq(unsig
pirq_query_unmask(irq);
rc = set_evtchn_to_irq(evtchn, irq);
- if (rc != 0) {
- pr_err("irq%d: Failed to set port to irq mapping (%d)\n",
- irq, rc);
- xen_evtchn_close(evtchn);
- return 0;
- }
+ if (rc)
+ goto err;
+
bind_evtchn_to_cpu(evtchn, 0);
info->evtchn = evtchn;
+ rc = xen_evtchn_port_setup(info);
+ if (rc)
+ goto err;
+
out:
unmask_evtchn(evtchn);
eoi_pirq(irq_get_irq_data(irq));
return 0;
+
+err:
+ pr_err("irq%d: Failed to set port to irq mapping (%d)\n", irq, rc);
+ xen_evtchn_close(evtchn);
+ return 0;
}
static unsigned int startup_pirq(struct irq_data *data)
Patches currently in stable-queue which might be from [email protected] are
queue-3.14/xen-events-avoid-null-pointer-dereference-in-dom0-on-large-machines.patch
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