xen/events: prevent calling evtchn_get on invalid channels
The event channel number provided to evtchn_get can be provided by
userspace, so needs to be checked against the maximum number of event
channels prior to using it to index into evtchn_to_irq.
Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index a3bcd61..e5e5812 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -1104,6 +1104,9 @@
struct irq_info *info;
int err = -ENOENT;
+ if (evtchn >= NR_EVENT_CHANNELS)
+ return -EINVAL;
+
mutex_lock(&irq_mapping_update_lock);
irq = evtchn_to_irq[evtchn];