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Commit ef31bef6 authored by Haiyang Zhang's avatar Haiyang Zhang Committed by David S. Miller
Browse files

net/hyperv: Fix data corruption in rndis_filter_receive() 



Limiting the memcpy to be the sizeof(struct rndis_message) can truncate
the message if there are Per-Packet-Info or Out-of-Band data.

In my earlier patch (commit 45326342), the unnecessary kmap_atomic and
kunmap_atomic surrounding this memcpy have been removed because the memory
in the receive buffer is always mapped. This memcpy is not necessary
either. To fix the bug, I removed the memcpy.

Signed-off-by: default avatarHaiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: default avatarK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent afd46503

drivers/net/hyperv/rndis_filter.c

+9 −24
Original line number Original line Diff line number Diff line
@@ -352,8 +352,7 @@ int rndis_filter_receive(struct hv_device *dev, 
{

{

	struct netvsc_device *net_dev = hv_get_drvdata(dev);

	struct netvsc_device *net_dev = hv_get_drvdata(dev);

	struct rndis_device *rndis_dev;

	struct rndis_device *rndis_dev;

	struct rndis_message rndis_msg;

	struct rndis_message *rndis_msg;

	struct rndis_message *rndis_hdr;

	struct net_device *ndev;

	struct net_device *ndev;





	if (!net_dev)

	if (!net_dev)
@@ -375,46 +374,32 @@ int rndis_filter_receive(struct hv_device *dev, 
		return -ENODEV;

		return -ENODEV;

	}

	}





	rndis_hdr = pkt->data;

	rndis_msg = pkt->data;



	/* Make sure we got a valid rndis message */

	if ((rndis_hdr->ndis_msg_type != REMOTE_NDIS_PACKET_MSG) &&

	    (rndis_hdr->msg_len > sizeof(struct rndis_message))) {

		netdev_err(ndev, "incoming rndis message buffer overflow "

			   "detected (got %u, max %zu)..marking it an error!\n",

			   rndis_hdr->msg_len,

			   sizeof(struct rndis_message));

	}



	memcpy(&rndis_msg, rndis_hdr,

		(rndis_hdr->msg_len > sizeof(struct rndis_message)) ?

			sizeof(struct rndis_message) :

			rndis_hdr->msg_len);





	dump_rndis_message(dev, &rndis_msg);

	dump_rndis_message(dev, rndis_msg);





	switch (rndis_msg.ndis_msg_type) {

	switch (rndis_msg->ndis_msg_type) {

	case REMOTE_NDIS_PACKET_MSG:

	case REMOTE_NDIS_PACKET_MSG:

		/* data msg */

		/* data msg */

		rndis_filter_receive_data(rndis_dev, &rndis_msg, pkt);

		rndis_filter_receive_data(rndis_dev, rndis_msg, pkt);

		break;

		break;





	case REMOTE_NDIS_INITIALIZE_CMPLT:

	case REMOTE_NDIS_INITIALIZE_CMPLT:

	case REMOTE_NDIS_QUERY_CMPLT:

	case REMOTE_NDIS_QUERY_CMPLT:

	case REMOTE_NDIS_SET_CMPLT:

	case REMOTE_NDIS_SET_CMPLT:

		/* completion msgs */

		/* completion msgs */

		rndis_filter_receive_response(rndis_dev, &rndis_msg);

		rndis_filter_receive_response(rndis_dev, rndis_msg);

		break;

		break;





	case REMOTE_NDIS_INDICATE_STATUS_MSG:

	case REMOTE_NDIS_INDICATE_STATUS_MSG:

		/* notification msgs */

		/* notification msgs */

		rndis_filter_receive_indicate_status(rndis_dev, &rndis_msg);

		rndis_filter_receive_indicate_status(rndis_dev, rndis_msg);

		break;

		break;

	default:

	default:

		netdev_err(ndev,

		netdev_err(ndev,

			"unhandled rndis message (type %u len %u)\n",

			"unhandled rndis message (type %u len %u)\n",

			   rndis_msg.ndis_msg_type,

			   rndis_msg->ndis_msg_type,

			   rndis_msg.msg_len);

			   rndis_msg->msg_len);

		break;

		break;

	}

	}