From: Matteo Croce <mcroce@redhat.com>
Date: Thu, 11 Apr 2019 12:26:33 +0200
Subject: net: thunderx: don't allow jumbo frames with XDP
Git-commit: 1f227d16083b2e280b7dde4ca78883d75593f2fd
Patch-mainline: v5.1-rc6
References: networking-stable-19_04_19
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: 05c773f52b96e ("net: thunderx: Add basic XDP support")
Signed-off-by: Matteo Croce <mcroce@redhat.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
drivers/net/ethernet/cavium/thunder/nicvf_main.c | 9 +++++++++
1 file changed, 9 insertions(+)
--- a/drivers/net/ethernet/cavium/thunder/nicvf_main.c
+++ b/drivers/net/ethernet/cavium/thunder/nicvf_main.c
@@ -1546,6 +1546,15 @@ static int nicvf_change_mtu(struct net_d
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))