diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c index 1bb2e2072a6a4078ca6953529970c0e6401cb83f..1db101415069726fc59d26443f773fc0432f52a6 100644 --- a/drivers/net/xen-netfront.c +++ b/drivers/net/xen-netfront.c @@ -36,7 +36,7 @@ #include #include #include -#include +#include #include #include #include @@ -547,6 +547,16 @@ static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev) unsigned int len = skb_headlen(skb); unsigned long flags; + /* If skb->len is too big for wire format, drop skb and alert + * user about misconfiguration. + */ + if (unlikely(skb->len > XEN_NETIF_MAX_TX_SIZE)) { + net_alert_ratelimited( + "xennet: skb->len = %u, too big for wire format\n", + skb->len); + goto drop; + } + slots = DIV_ROUND_UP(offset + len, PAGE_SIZE) + xennet_count_skb_frag_slots(skb); if (unlikely(slots > MAX_SKB_FRAGS + 1)) { @@ -1058,7 +1068,8 @@ static int xennet_poll(struct napi_struct *napi, int budget) static int xennet_change_mtu(struct net_device *dev, int mtu) { - int max = xennet_can_sg(dev) ? 65535 - ETH_HLEN : ETH_DATA_LEN; + int max = xennet_can_sg(dev) ? + XEN_NETIF_MAX_TX_SIZE - MAX_TCP_HEADER : ETH_DATA_LEN; if (mtu > max) return -EINVAL; @@ -1362,6 +1373,8 @@ static struct net_device *xennet_create_dev(struct xenbus_device *dev) SET_ETHTOOL_OPS(netdev, &xennet_ethtool_ops); SET_NETDEV_DEV(netdev, &dev->dev); + netif_set_gso_max_size(netdev, XEN_NETIF_MAX_TX_SIZE - MAX_TCP_HEADER); + np->netdev = netdev; netif_carrier_off(netdev); diff --git a/include/xen/interface/io/netif.h b/include/xen/interface/io/netif.h index 9dfc12000980f6e4a036008ca39d7460fa25534f..58fadcac33a17c004c1cdf17557bc570b8a4f33e 100644 --- a/include/xen/interface/io/netif.h +++ b/include/xen/interface/io/netif.h @@ -47,6 +47,7 @@ #define _XEN_NETTXF_extra_info (3) #define XEN_NETTXF_extra_info (1U<<_XEN_NETTXF_extra_info) +#define XEN_NETIF_MAX_TX_SIZE 0xFFFF struct xen_netif_tx_request { grant_ref_t gref; /* Reference to buffer page */ uint16_t offset; /* Offset within buffer page */