If a guest neglected to register (secondary) indicators but still runs
with notifications enabled, we might end up writing to guest zero;
avoid this by checking for valid indicators and only writing to the
guest and generating an interrupt if indicators have been setup.
Cc: qemu-sta...@nongnu.org
Signed-off-by: Cornelia Huck <cornelia.h...@de.ibm.com>
---
hw/s390x/virtio-ccw.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
index 56539d3..1c6bd21 100644
--- a/hw/s390x/virtio-ccw.c
+++ b/hw/s390x/virtio-ccw.c
@@ -752,10 +752,16 @@ static void virtio_ccw_notify(DeviceState *d, uint16_t
vector)
}
if (vector < VIRTIO_PCI_QUEUE_MAX) {
+ if (!dev->indicators) {
+ return;
+ }
indicators = ldq_phys(dev->indicators);
indicators |= 1ULL << vector;
stq_phys(dev->indicators, indicators);
} else {
+ if (!dev->indicators2) {
+ return;
+ }
vector = 0;
indicators = ldq_phys(dev->indicators2);
indicators |= 1ULL << vector;
--
1.7.9.5
