diff options
| author | Juergen Gross <jgross@suse.com> | 2015-02-26 06:52:05 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-03-26 15:06:56 +0100 |
| commit | a5b8311fe0adc3d83b353c8e13899ea71bc51723 (patch) | |
| tree | ba692ddf6f360c8c231e7ff933a42338199ef35f /drivers/xen | |
| parent | 472cd1f6c9bfb48d5bab283dbf123837dd4e2cbb (diff) | |
xen/events: avoid NULL pointer dereference in dom0 on large machines
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 <jgross@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/xen')
| -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 f4a9e3311297..c8860a8757ac 100644 --- a/drivers/xen/events/events_base.c +++ b/drivers/xen/events/events_base.c @@ -547,20 +547,26 @@ 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) |