mlx4_en: Fix out of bounds array access

When searching for a free entry in either mlx4_register_vlan() or
mlx4_register_mac(), and there is no free entry, the loop terminates without
updating the local variable free thus causing out of array bounds access. Fix
this by adding a proper check outside the loop.

Signed-off-by: Eli Cohen <eli@mellanox.co.il>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 11 insertions, 0 deletions

diff --git a/drivers/net/mlx4/port.c b/drivers/net/mlx4/port.c
index 606aa58afde..8674ad5764c 100644
--- a/drivers/net/mlx4/port.c
+++ b/drivers/net/mlx4/port.c
@@ -111,6 +111,12 @@ int mlx4_register_mac(struct mlx4_dev *dev, u8 port, u64 mac, int *index)
                         goto out;
                 }
         }
+
+        if (free < 0) {
+                err = -ENOMEM;
+                goto out;
+        }
+
         mlx4_dbg(dev, "Free MAC index is %d\n", free);
 
         if (table->total == table->max) {
@@ -205,6 +211,11 @@ int mlx4_register_vlan(struct mlx4_dev *dev, u8 port, u16 vlan, int *index)
                 }
         }
 
+        if (free < 0) {
+                err = -ENOMEM;
+                goto out;
+        }
+
         if (table->total == table->max) {
                 /* No free vlan entries */
                 err = -ENOSPC;