[PATCH] vhost: reject zero-size IOTLB INVALIDATE

From: xiongweimin <redacted>

Reject VHOST_IOTLB_INVALIDATE messages with size == 0 to prevent
iova + size - 1 from underflowing to U64_MAX, which would
incorrectly delete the entire IOTLB.

Signed-off-by: xiongweimin <redacted>
---
 drivers/vhost/vhost.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c

index 3c080c454e374cabd7321416ed92c5f7d3135254..xxxxxxxxxx 100644

--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c

@@ -1656,6 +1656,10 @@ static int vhost_process_iotlb_msg(struct vhost_dev *dev, u32 asid,
 		if (!dev->iotlb) {
 			ret = -EFAULT;
 			break;
+		}
+		if (!msg->size) {
+			ret = -EINVAL;
+			break;
 		}
 		vhost_vq_meta_reset(dev);
 		vhost_iotlb_del_range(dev->iotlb, msg->iova,
--

2.39.3