[PATCH net 2/4] virtio_net: Add hash_key_length check

[Philo Lu]

Add hash_key_length check in virtnet_probe() to avoid possible out of
bound errors when setting/reading the hash key.

Fixes: c7114b1249fa ("drivers/net/virtio_net: Added basic RSS support.")
Signed-off-by: Philo Lu <lulie@xxxxxxxxxxxxxxxxx>
Signed-off-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>
---
 drivers/net/virtio_net.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 75c1ff4efd13..acc3e5dc112e 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -6451,6 +6451,12 @@ static int virtnet_probe(struct virtio_device *vdev)
 	if (vi->has_rss || vi->has_rss_hash_report) {
 		vi->rss_key_size =
 			virtio_cread8(vdev, offsetof(struct virtio_net_config, rss_max_key_size));
+		if (vi->rss_key_size > VIRTIO_NET_RSS_MAX_KEY_SIZE) {
+			dev_err(&vdev->dev, "rss_max_key_size=%u exceeds the limit %u.\n",
+				vi->rss_key_size, VIRTIO_NET_RSS_MAX_KEY_SIZE);
+			err = -EINVAL;
+			goto free;
+		}
 
 		vi->rss_hash_types_supported =
 		    virtio_cread32(vdev, offsetof(struct virtio_net_config, supported_hash_types));
-- 
2.32.0.3.g01195cf9f