IB/core: When marshaling ucma path from user-space, clear unused fields

When marshaling a user path to the kernel struct ib_sa_path, we need
to zero smac and dmac and set the vlan id to the "no vlan" value.

This is to ensure that Ethernet attributes are not used with
InfiniBand QPs.

Fixes: dd5f03be ("IB/core: Ethernet L2 attributes in verbs/cm structures")
Signed-off-by: Ilya Nelkenbaum <ilyan@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

drivers/infiniband/core/ucma.c

@@ -1124,6 +1124,9 @@ static int ucma_set_ib_path(struct ucma_context *ctx,
 	if (!optlen)
 		return -EINVAL;
 
+	memset(&sa_path, 0, sizeof(sa_path));
+	sa_path.vlan_id = 0xffff;
+
 	ib_sa_unpack_path(path_data->path_rec, &sa_path);
 	ret = rdma_set_ib_paths(ctx->cm_id, &sa_path, 1);
 	if (ret)