From 7c4869761d7f2e0a3f806a5359eea5d2473ec5d5 Mon Sep 17 00:00:00 2001 From: Cornelia Huck Date: Tue, 23 Apr 2013 17:15:19 +0200 Subject: virtio-ccw: Check indicators location. 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-stable@nongnu.org Signed-off-by: Cornelia Huck --- hw/s390x/virtio-ccw.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'hw/s390x') diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c index 56e4872e11..b857413fa4 100644 --- a/hw/s390x/virtio-ccw.c +++ b/hw/s390x/virtio-ccw.c @@ -742,10 +742,16 @@ 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; -- cgit v1.2.1