net/igb/e1000/e1000e: more robust ethtool duplex/speed configuration

This makes sure that one cannot request a 99Mbps full-duplex and get a
100Mbps half-duplex configuration in return due to the way the
speed/duplex parameters are handled internally.

Tested: e1000 works
Signed-off-by: David Decotigny <decot@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 16 insertions, 8 deletions

diff --git a/drivers/net/e1000e/ethtool.c b/drivers/net/e1000e/ethtool.c
index 12f1ee250522..859d0d3af6c9 100644
--- a/drivers/net/e1000e/ethtool.c
+++ b/drivers/net/e1000e/ethtool.c
@@ -200,20 +200,25 @@ static int e1000_get_settings(struct net_device *netdev,
         return 0;
 }
 
-static int e1000_set_spd_dplx(struct e1000_adapter *adapter, u16 spddplx)
+static int e1000_set_spd_dplx(struct e1000_adapter *adapter, u32 spd, u8 dplx)
 {
         struct e1000_mac_info *mac = &adapter->hw.mac;
 
         mac->autoneg = 0;
 
+        /* Make sure dplx is at most 1 bit and lsb of speed is not set
+         * for the switch() below to work */
+        if ((spd & 1) || (dplx & ~1))
+                goto err_inval;
+
         /* Fiber NICs only allow 1000 gbps Full duplex */
         if ((adapter->hw.phy.media_type == e1000_media_type_fiber) &&
-                spddplx != (SPEED_1000 + DUPLEX_FULL)) {
-                e_err("Unsupported Speed/Duplex configuration\n");
-                return -EINVAL;
+            spd != SPEED_1000 &&
+            dplx != DUPLEX_FULL) {
+                goto err_inval;
         }
 
-        switch (spddplx) {
+        switch (spd + dplx) {
         case SPEED_10 + DUPLEX_HALF:
                 mac->forced_speed_duplex = ADVERTISE_10_HALF;
                 break;
@@ -232,10 +237,13 @@ static int e1000_set_spd_dplx(struct e1000_adapter *adapter, u16 spddplx)
                 break;
         case SPEED_1000 + DUPLEX_HALF: /* not supported */
         default:
-                e_err("Unsupported Speed/Duplex configuration\n");
-                return -EINVAL;
+                goto err_inval;
         }
         return 0;
+
+err_inval:
+        e_err("Unsupported Speed/Duplex configuration\n");
+        return -EINVAL;
 }
 
 static int e1000_set_settings(struct net_device *netdev,
@@ -272,7 +280,7 @@ static int e1000_set_settings(struct net_device *netdev,
                         hw->fc.requested_mode = e1000_fc_default;
         } else {
                 u32 speed = ethtool_cmd_speed(ecmd);
-                if (e1000_set_spd_dplx(adapter, speed + ecmd->duplex)) {
+                if (e1000_set_spd_dplx(adapter, speed, ecmd->duplex)) {
                         clear_bit(__E1000_RESETTING, &adapter->state);
                         return -EINVAL;
                 }