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 39eb7a65bb9f6a6137ffe13c4c2e776720311db1..a276a32d57f24374444ec06c02b3707fec8fae0a 100644 (file)
--- 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 */

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c
index a2831773431a6c19d185b2e82e50897aaf7ef7d8..3da4737620cb3fbf50e16c2cf61de3dbfd3e2355 100644 (file)
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c
@@ -89,6 +89,9 @@ static void stmmac_default_data(struct plat_stmmacenet_data *plat)
 
        /* Set default value for unicast filter entries */
        plat->unicast_filter_entries = 1;
+
+       /* Set the maxmtu to a default of JUMBO_LEN */
+       plat->maxmtu = JUMBO_LEN;
 }
 
 static int quark_default_data(struct plat_stmmacenet_data *plat,
@@ -126,6 +129,9 @@ static int quark_default_data(struct plat_stmmacenet_data *plat,
        /* Set default value for unicast filter entries */
        plat->unicast_filter_entries = 1;
 
+       /* Set the maxmtu to a default of JUMBO_LEN */
+       plat->maxmtu = JUMBO_LEN;
+
        return 0;
 }