igb: Check if num of q_vectors is smaller than max before array access

Ensure that the adapter->q_vector[MAX_Q_VECTORS] array isn't accessed
beyond its size. It was fixed by using a local variable num_q_vectors
as a limit for loop index, and ensure that num_q_vectors is not bigger
than MAX_Q_VECTORS.

Fixes: 047e0030f1e6 ("igb: add new data structure for handling interrupts and NAPI")
Signed-off-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Reviewed-by: Grzegorz Siwik <grzegorz.siwik@intel.com>
Reviewed-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com>
Reviewed-by: Slawomir Laba <slawomirx.laba@intel.com>
Reviewed-by: Sylwester Dziedziuch <sylwesterx.dziedziuch@intel.com>
Reviewed-by: Mateusz Palczewski <mateusz.placzewski@intel.com>
Tested-by: Tony Brelinski <tonyx.brelinski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
index abc239b..9470ba8 100644 (file)
--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/drivers/net/ethernet/intel/igb/igb_main.c
@@ -931,6 +931,7 @@ static void igb_configure_msix(struct igb_adapter *adapter)
  **/
 static int igb_request_msix(struct igb_adapter *adapter)
 {
+       unsigned int num_q_vectors = adapter->num_q_vectors;
        struct net_device *netdev = adapter->netdev;
        int i, err = 0, vector = 0, free_vector = 0;
 
@@ -939,7 +940,13 @@ static int igb_request_msix(struct igb_adapter *adapter)
        if (err)
                goto err_out;
 
-       for (i = 0; i < adapter->num_q_vectors; i++) {
+       if (num_q_vectors > MAX_Q_VECTORS) {
+               num_q_vectors = MAX_Q_VECTORS;
+               dev_warn(&adapter->pdev->dev,
+                        "The number of queue vectors (%d) is higher than max allowed (%d)\n",
+                        adapter->num_q_vectors, MAX_Q_VECTORS);
+       }
+       for (i = 0; i < num_q_vectors; i++) {
                struct igb_q_vector *q_vector = adapter->q_vector[i];
 
                vector++;