[PATCH v2] wifi: iwlegacy: Check rate_idx range after addition

[Stanislaw Gruszka <stf_xl@wp.pl>]

Limit rate_idx to IL_LAST_OFDM_RATE for 5GHz band for thinkable case
the index is incorrect.

Reported-by: Fedor Pchelkin <pchelkin@ispras.ru>
Reported-by: Alexei Safin <a.safin@rosa.ru>
Signed-off-by: Stanislaw Gruszka <stf_xl@wp.pl>
---
v1 -> v2: 
 - just add check one possible case the index could be incorrect,
   instead of doing broader changes.

 drivers/net/wireless/intel/iwlegacy/4965-mac.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/intel/iwlegacy/4965-mac.c b/drivers/net/wireless/intel/iwlegacy/4965-mac.c
index dc8c408902e6..4d2148147b94 100644
--- a/drivers/net/wireless/intel/iwlegacy/4965-mac.c
+++ b/drivers/net/wireless/intel/iwlegacy/4965-mac.c
@@ -1575,8 +1575,11 @@ il4965_tx_cmd_build_rate(struct il_priv *il,
 	    || rate_idx > RATE_COUNT_LEGACY)
 		rate_idx = rate_lowest_index(&il->bands[info->band], sta);
 	/* For 5 GHZ band, remap mac80211 rate indices into driver indices */
-	if (info->band == NL80211_BAND_5GHZ)
+	if (info->band == NL80211_BAND_5GHZ) {
 		rate_idx += IL_FIRST_OFDM_RATE;
+		if (rate_idx > IL_LAST_OFDM_RATE)
+			rate_idx = IL_LAST_OFDM_RATE;
+	}
 	/* Get PLCP rate for tx_cmd->rate_n_flags */
 	rate_plcp = il_rates[rate_idx].plcp;
 	/* Zero out flags for this packet */
-- 
2.25.4