Merge branch 'hv_netvsc-Fix-send-indirection-table-offset'

Haiyang Zhang says:

====================
hv_netvsc: Fix send indirection table offset

Fix send indirection table offset issues related to guest and
host bugs.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/hyperv/hyperv_net.h

@@ -609,7 +609,8 @@ struct nvsp_5_send_indirect_table {
 	/* The number of entries in the send indirection table */
 	u32 count;
 
-	/* The offset of the send indirection table from top of this struct.
+	/* The offset of the send indirection table from the beginning of
+	 * struct nvsp_message.
 	 * The send indirection table tells which channel to put the send
 	 * traffic on. Each entry is a channel number.
 	 */

drivers/net/hyperv/netvsc.c

@@ -1178,20 +1178,39 @@ static int netvsc_receive(struct net_device *ndev,
 }
 
 static void netvsc_send_table(struct net_device *ndev,
-			      const struct nvsp_message *nvmsg)
+			      struct netvsc_device *nvscdev,
+			      const struct nvsp_message *nvmsg,
+			      u32 msglen)
 {
 	struct net_device_context *net_device_ctx = netdev_priv(ndev);
-	u32 count, *tab;
+	u32 count, offset, *tab;
 	int i;
 
 	count = nvmsg->msg.v5_msg.send_table.count;
+	offset = nvmsg->msg.v5_msg.send_table.offset;
+
 	if (count != VRSS_SEND_TAB_SIZE) {
 		netdev_err(ndev, "Received wrong send-table size:%u\n", count);
 		return;
 	}
 
-	tab = (u32 *)((unsigned long)&nvmsg->msg.v5_msg.send_table +
-		      nvmsg->msg.v5_msg.send_table.offset);
+	/* If negotiated version <= NVSP_PROTOCOL_VERSION_6, the offset may be
+	 * wrong due to a host bug. So fix the offset here.
+	 */
+	if (nvscdev->nvsp_version <= NVSP_PROTOCOL_VERSION_6 &&
+	    msglen >= sizeof(struct nvsp_message_header) +
+	    sizeof(union nvsp_6_message_uber) + count * sizeof(u32))
+		offset = sizeof(struct nvsp_message_header) +
+			 sizeof(union nvsp_6_message_uber);
+
+	/* Boundary check for all versions */
+	if (offset > msglen - count * sizeof(u32)) {
+		netdev_err(ndev, "Received send-table offset too big:%u\n",
+			   offset);
+		return;
+	}
+
+	tab = (void *)nvmsg + offset;
 
 	for (i = 0; i < count; i++)
 		net_device_ctx->tx_table[i] = tab[i];
@@ -1209,12 +1228,14 @@ static void netvsc_send_vf(struct net_device *ndev,
 		    net_device_ctx->vf_alloc ? "added" : "removed");
 }
 
-static  void netvsc_receive_inband(struct net_device *ndev,
-				   const struct nvsp_message *nvmsg)
+static void netvsc_receive_inband(struct net_device *ndev,
+				  struct netvsc_device *nvscdev,
+				  const struct nvsp_message *nvmsg,
+				  u32 msglen)
 {
 	switch (nvmsg->hdr.msg_type) {
 	case NVSP_MSG5_TYPE_SEND_INDIRECTION_TABLE:
-		netvsc_send_table(ndev, nvmsg);
+		netvsc_send_table(ndev, nvscdev, nvmsg, msglen);
 		break;
 
 	case NVSP_MSG4_TYPE_SEND_VF_ASSOCIATION:
@@ -1232,6 +1253,7 @@ static int netvsc_process_raw_pkt(struct hv_device *device,
 {
 	struct vmbus_channel *channel = nvchan->channel;
 	const struct nvsp_message *nvmsg = hv_pkt_data(desc);
+	u32 msglen = hv_pkt_datalen(desc);
 
 	trace_nvsp_recv(ndev, channel, nvmsg);
 
@@ -1247,7 +1269,7 @@ static int netvsc_process_raw_pkt(struct hv_device *device,
 		break;
 
 	case VM_PKT_DATA_INBAND:
-		netvsc_receive_inband(ndev, nvmsg);
+		netvsc_receive_inband(ndev, net_device, nvmsg, msglen);
 		break;
 
 	default: