[PATCH 4.19 059/120] igb: Check if num of q_vectors is smaller than max before array access

[Greg Kroah-Hartman]

From: Aleksandr Loktionov <aleksandr.loktionov@xxxxxxxxx>

[ Upstream commit 6c19d772618fea40d9681f259368f284a330fd90 ]

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@xxxxxxxxx>
Reviewed-by: Grzegorz Siwik <grzegorz.siwik@xxxxxxxxx>
Reviewed-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@xxxxxxxxx>
Reviewed-by: Slawomir Laba <slawomirx.laba@xxxxxxxxx>
Reviewed-by: Sylwester Dziedziuch <sylwesterx.dziedziuch@xxxxxxxxx>
Reviewed-by: Mateusz Palczewski <mateusz.placzewski@xxxxxxxxx>
Tested-by: Tony Brelinski <tonyx.brelinski@xxxxxxxxx>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/net/ethernet/intel/igb/igb_main.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
index 8558d2e4ec18..243e304c35cd 100644
--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/drivers/net/ethernet/intel/igb/igb_main.c
@@ -938,6 +938,7 @@ 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;
 
@@ -946,7 +947,13 @@ 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++;
-- 
2.30.2