igb: limit minimum mtu to 68 to keep ip bound to interface

Limit the minimum mtu to 68 in order to prevent ip from being unbound from
the interface.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/igb/igb_main.c b/drivers/net/igb/igb_main.c
index 264ff00..846e64f 100644 (file)
--- a/drivers/net/igb/igb_main.c
+++ b/drivers/net/igb/igb_main.c
@@ -3709,8 +3709,7 @@ static int igb_change_mtu(struct net_device *netdev, int new_mtu)
        int max_frame = new_mtu + ETH_HLEN + ETH_FCS_LEN;
        u32 rx_buffer_len, i;
 
-       if ((max_frame < ETH_ZLEN + ETH_FCS_LEN) ||
-           (max_frame > MAX_JUMBO_FRAME_SIZE)) {
+       if ((new_mtu < 68) || (max_frame > MAX_JUMBO_FRAME_SIZE)) {
                dev_err(&pdev->dev, "Invalid MTU setting\n");
                return -EINVAL;
        }