net: stmmac: fix maxmtu assignment to be within valid range
There is no checking valid value of maxmtu when getting it from
device tree. This resolution added the checking condition to
ensure the assignment is made within a valid range.
Signed-off-by: Kweh, Hock Leong <hock.leong.kweh@intel.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 39eb7a6..a276a32 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -3319,8 +3319,16 @@ int stmmac_dvr_probe(struct device *device,
ndev->max_mtu = JUMBO_LEN;
else
ndev->max_mtu = SKB_MAX_HEAD(NET_SKB_PAD + NET_IP_ALIGN);
- if (priv->plat->maxmtu < ndev->max_mtu)
+ /* Will not overwrite ndev->max_mtu if plat->maxmtu > ndev->max_mtu
+ * as well as plat->maxmtu < ndev->min_mtu which is a invalid range.
+ */
+ if ((priv->plat->maxmtu < ndev->max_mtu) &&
+ (priv->plat->maxmtu >= ndev->min_mtu))
ndev->max_mtu = priv->plat->maxmtu;
+ else if (priv->plat->maxmtu < ndev->min_mtu)
+ netdev_warn(priv->dev,
+ "%s: warning: maxmtu having invalid value (%d)\n",
+ __func__, priv->plat->maxmtu);
if (flow_ctrl)
priv->flow_ctrl = FLOW_AUTO; /* RX/TX pause on */