mac80211: don't sanitize invalid rates

I found this bug while poking around with a pure-gn AP.

Commit:
cfg80211/mac80211: Use more generic bitrate mask for rate control

Added some sanity checks to ensure that each tx rate index
is included in the configured mask and it would change any
rate indexes if it wasn't.

But, the current implementation doesn't take into account
that the invalid rate index "-1" has a special meaning
(= no further attempts) and it should not be "changed".

Signed-off-by: Christian Lamparter <chunkeey@googlemail.com>
Cc: stable@kernel.org
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/net/mac80211/rate.c b/net/mac80211/rate.c
index 809cf230d251bccec01c32b6e60608f19ac32cf3..33f76993da081fcd73c10cad2bf1328c46d83299 100644 (file)
--- a/net/mac80211/rate.c
+++ b/net/mac80211/rate.c
@@ -329,6 +329,9 @@ void rate_control_get_rate(struct ieee80211_sub_if_data *sdata,
                 * if needed.
                 */
                for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
+                       /* Skip invalid rates */
+                       if (info->control.rates[i].idx < 0)
+                               break;
                        /* Rate masking supports only legacy rates for now */
                        if (info->control.rates[i].flags & IEEE80211_TX_RC_MCS)
                                continue;