From 3de9e65f011b95235a789b12abc4730570cdb737 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Fri, 13 Sep 2013 20:44:20 +0000 Subject: [PATCH] igbvf: integer wrapping bug setting the mtu If new_mtu is very large then "new_mtu + ETH_HLEN + ETH_FCS_LEN" can wrap and the check on the next line can underflow. This is one of those bugs which can be triggered by the user if you have namespaces configured. Also since this is something the user can trigger then we don't want to have dev_err() message. This is a static checker fix and I'm not sure what the impact is. Signed-off-by: Dan Carpenter Tested-by: Aaron Brown Tested-by: Sibai Li Sibai.li@intel.com> Signed-off-by: Jeff Kirsher --- drivers/net/ethernet/intel/igbvf/netdev.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/net/ethernet/intel/igbvf/netdev.c b/drivers/net/ethernet/intel/igbvf/netdev.c index 93eb7ee..f48ae71 100644 --- a/drivers/net/ethernet/intel/igbvf/netdev.c +++ b/drivers/net/ethernet/intel/igbvf/netdev.c @@ -2343,10 +2343,9 @@ static int igbvf_change_mtu(struct net_device *netdev, int new_mtu) struct igbvf_adapter *adapter = netdev_priv(netdev); int max_frame = new_mtu + ETH_HLEN + ETH_FCS_LEN; - if ((new_mtu < 68) || (max_frame > MAX_JUMBO_FRAME_SIZE)) { - dev_err(&adapter->pdev->dev, "Invalid MTU setting\n"); + if (new_mtu < 68 || new_mtu > INT_MAX - ETH_HLEN - ETH_FCS_LEN || + max_frame > MAX_JUMBO_FRAME_SIZE) return -EINVAL; - } #define MAX_STD_JUMBO_FRAME_SIZE 9234 if (max_frame > MAX_STD_JUMBO_FRAME_SIZE) { -- 2.7.4