iwmc3200wifi: add a range check to iwm_cfg80211_get_key()

Smatch complains that "key_index" is capped at 5 in nl80211_get_key()
but iwm->keys[] only has 4 elements.  I don't know if this is really
needed, but the other ->get_key() implementations seemed to check
for overflows so I've added a check here.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/drivers/net/wireless/iwmc3200wifi/cfg80211.c b/drivers/net/wireless/iwmc3200wifi/cfg80211.c
index ed57e440280..c42be81e979 100644
--- a/drivers/net/wireless/iwmc3200wifi/cfg80211.c
+++ b/drivers/net/wireless/iwmc3200wifi/cfg80211.c
@@ -187,13 +187,17 @@ static int iwm_cfg80211_get_key(struct wiphy *wiphy, struct net_device *ndev,
                                                  struct key_params*))
 {
         struct iwm_priv *iwm = ndev_to_iwm(ndev);
-        struct iwm_key *key = &iwm->keys[key_index];
+        struct iwm_key *key;
         struct key_params params;
 
         IWM_DBG_WEXT(iwm, DBG, "Getting key %d\n", key_index);
 
+        if (key_index >= IWM_NUM_KEYS)
+                return -ENOENT;
+
         memset(&params, 0, sizeof(params));
 
+        key = &iwm->keys[key_index];
         params.cipher = key->cipher;
         params.key_len = key->key_len;
         params.seq_len = key->seq_len;