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| author | Juergen Gross <jgross@suse.com> | 2015-02-26 06:52:05 +0100 |
|---|---|---|
| committer | David Vrabel <david.vrabel@citrix.com> | 2015-03-06 13:16:32 +0000 |
| commit | 85e40b0539b24518c8bdf63e2605c8522377d00f (patch) | |
| tree | c495ad825da2b79d0a22987631826c1c370d4dc4 /drivers | |
| parent | 604b91fee4fc53ddc83c221c9bbce771898ec872 (diff) | |
| download | linux-85e40b0539b24518c8bdf63e2605c8522377d00f.tar.bz2 | |
xen/events: avoid NULL pointer dereference in dom0 on large machines
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 <jgross@suse.com>
Cc: <stable@vger.kernel.org> # 3.14+
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/xen/events/events_base.c | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c index b4bca2d4a7e5..70fba973a107 100644 --- a/drivers/xen/events/events_base.c +++ b/drivers/xen/events/events_base.c @@ -526,20 +526,26 @@ static unsigned int __startup_pirq(unsigned int irq) 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) |