From 5bdba84878be2411e6745ebc7e6f47f83dd92864 Mon Sep 17 00:00:00 2001 From: Matteo Croce Date: Thu, 11 Apr 2019 12:26:33 +0200 Subject: [PATCH] net: thunderx: don't allow jumbo frames with XDP The thunderx driver forbids to load an eBPF program if the MTU is too high, but this can be circumvented by loading the eBPF, then raising the MTU. Fix this by limiting the MTU if an eBPF program is already loaded. Fixes: c47ef23d9a89e ("net: thunderx: Add basic XDP support") Signed-off-by: Matteo Croce Acked-by: Jesper Dangaard Brouer Signed-off-by: David S. Miller --- drivers/net/ethernet/cavium/thunder/nicvf_main.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/net/ethernet/cavium/thunder/nicvf_main.c b/drivers/net/ethernet/cavium/thunder/nicvf_main.c index debc8c861c6bd..c032bef1b776d 100644 --- a/drivers/net/ethernet/cavium/thunder/nicvf_main.c +++ b/drivers/net/ethernet/cavium/thunder/nicvf_main.c @@ -1589,6 +1589,15 @@ static int nicvf_change_mtu(struct net_device *netdev, int new_mtu) struct nicvf *nic = netdev_priv(netdev); int orig_mtu = netdev->mtu; + /* For now just support only the usual MTU sized frames, + * plus some headroom for VLAN, QinQ. + */ + if (nic->xdp_prog && new_mtu > MAX_XDP_MTU) { + netdev_warn(netdev, "Jumbo frames not yet supported with XDP, current MTU %d.\n", + netdev->mtu); + return -EINVAL; + } + netdev->mtu = new_mtu; if (!netif_running(netdev)) -- 2.39.5