ixgbe: dcb: check setup_tc return codes

dcb netlink code calls setup_tc to init hardware traffic classes
to use for DCB. At some call sites the return values are not
checked for errors and in one case may return -EINVAL back to
the net/dcbnl.c caller which is expecting a u8.

This fixes some smatch hits and although failures are never
seen in practive its best to check return codes.

Reported-by: Dan Carenter <dan.carpenter@oracle.com>
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

1 files changed, 18 insertions, 8 deletions

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_dcb_nl.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_dcb_nl.c
index 79a92fe987b9..95e5d11bb555 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_dcb_nl.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_dcb_nl.c
@@ -111,7 +111,7 @@ static u8 ixgbe_dcbnl_get_state(struct net_device *netdev)
 
 static u8 ixgbe_dcbnl_set_state(struct net_device *netdev, u8 state)
 {
-        u8 err = 0;
+        int err = 0;
         u8 prio_tc[MAX_USER_PRIORITY] = {0};
         int i;
         struct ixgbe_adapter *adapter = netdev_priv(netdev);
@@ -122,7 +122,7 @@ static u8 ixgbe_dcbnl_set_state(struct net_device *netdev, u8 state)
 
         /* verify there is something to do, if not then exit */
         if (!!state != !(adapter->flags & IXGBE_FLAG_DCB_ENABLED))
-                return err;
+                goto out;
 
         if (state > 0) {
                 err = ixgbe_setup_tc(netdev, adapter->dcb_cfg.num_tcs.pg_tcs);
@@ -131,10 +131,14 @@ static u8 ixgbe_dcbnl_set_state(struct net_device *netdev, u8 state)
                 err = ixgbe_setup_tc(netdev, 0);
         }
 
+        if (err)
+                goto out;
+
         for (i = 0; i < IEEE_8021QAZ_MAX_TCS; i++)
                 netdev_set_prio_tc_map(netdev, i, prio_tc[i]);
 
-        return err;
+out:
+        return err ? 1 : 0;
 }
 
 static void ixgbe_dcbnl_get_perm_hw_addr(struct net_device *netdev,
@@ -581,7 +585,7 @@ static int ixgbe_dcbnl_ieee_setets(struct net_device *dev,
 {
         struct ixgbe_adapter *adapter = netdev_priv(dev);
         int max_frame = dev->mtu + ETH_HLEN + ETH_FCS_LEN;
-        int i;
+        int i, err = 0;
         __u8 max_tc = 0;
 
         if (!(adapter->dcbx_cap & DCB_CAP_DCBX_VER_IEEE))
@@ -608,12 +612,17 @@ static int ixgbe_dcbnl_ieee_setets(struct net_device *dev,
                 return -EINVAL;
 
         if (max_tc != netdev_get_num_tc(dev))
-                ixgbe_setup_tc(dev, max_tc);
+                err = ixgbe_setup_tc(dev, max_tc);
+
+        if (err)
+                goto err_out;
 
         for (i = 0; i < IEEE_8021QAZ_MAX_TCS; i++)
                 netdev_set_prio_tc_map(dev, i, ets->prio_tc[i]);
 
-        return ixgbe_dcb_hw_ets(&adapter->hw, ets, max_frame);
+        err = ixgbe_dcb_hw_ets(&adapter->hw, ets, max_frame);
+err_out:
+        return err;
 }
 
 static int ixgbe_dcbnl_ieee_getpfc(struct net_device *dev,
@@ -726,6 +735,7 @@ static u8 ixgbe_dcbnl_setdcbx(struct net_device *dev, u8 mode)
         struct ixgbe_adapter *adapter = netdev_priv(dev);
         struct ieee_ets ets = {0};
         struct ieee_pfc pfc = {0};
+        int err = 0;
 
         /* no support for LLD_MANAGED modes or CEE+IEEE */
         if ((mode & DCB_CAP_DCBX_LLD_MANAGED) ||
@@ -756,10 +766,10 @@ static u8 ixgbe_dcbnl_setdcbx(struct net_device *dev, u8 mode)
                  */
                 ixgbe_dcbnl_ieee_setets(dev, &ets);
                 ixgbe_dcbnl_ieee_setpfc(dev, &pfc);
-                ixgbe_setup_tc(dev, 0);
+                err = ixgbe_setup_tc(dev, 0);
         }
 
-        return 0;
+        return err ? 1 : 0;
 }
 
 const struct dcbnl_rtnl_ops dcbnl_ops = {