From 6f3180afbb22106d96a1320e175562f36a4d3506 Mon Sep 17 00:00:00 2001 From: Jason Wang Date: Tue, 23 Jan 2018 17:27:26 +0800 Subject: vhost: do not try to access device IOTLB when not initialized The code will try to access dev->iotlb when processing VHOST_IOTLB_INVALIDATE even if it was not initialized which may lead to NULL pointer dereference. Fixes this by check dev->iotlb before. Fixes: 6b1e6cc7855b0 ("vhost: new device IOTLB API") Signed-off-by: Jason Wang Acked-by: Michael S. Tsirkin Signed-off-by: David S. Miller --- drivers/vhost/vhost.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 549771a0cd8b..5727b186b3ca 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -1015,6 +1015,10 @@ static int vhost_process_iotlb_msg(struct vhost_dev *dev, vhost_iotlb_notify_vq(dev, msg); break; case VHOST_IOTLB_INVALIDATE: + if (!dev->iotlb) { + ret = -EFAULT; + break; + } vhost_vq_meta_reset(dev); vhost_del_umem_range(dev->iotlb, msg->iova, msg->iova + msg->size - 1); -- cgit v1.2.3-59-g8ed1b