mac80211: minstrel_ht: fix out-of-bound in minstrel_ht_set_best_prob_rate
Patch fixes this splat
BUG: KASAN: slab-out-of-bounds in minstrel_ht_update_stats.isra.7+0x6e1/0x9e0
[mac80211] at addr ffff8800cee640f4 Read of size 4 by task swapper/3/0
Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>
Link: http://lkml.kernel.org/r/CALYGNiNyJhSaVnE35qS6UCGaSb2Dx1_i5HcRavuOX14oTz2P+w@mail.gmail.com
Acked-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/rc80211_minstrel_ht.c b/net/mac80211/rc80211_minstrel_ht.c
index 3928dbd..93bf2b7 100644
--- a/net/mac80211/rc80211_minstrel_ht.c
+++ b/net/mac80211/rc80211_minstrel_ht.c
@@ -414,15 +414,16 @@
(max_tp_group != MINSTREL_CCK_GROUP))
return;
+ max_gpr_group = mg->max_group_prob_rate / MCS_GROUP_RATES;
+ max_gpr_idx = mg->max_group_prob_rate % MCS_GROUP_RATES;
+ max_gpr_prob = mi->groups[max_gpr_group].rates[max_gpr_idx].prob_ewma;
+
if (mrs->prob_ewma > MINSTREL_FRAC(75, 100)) {
cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx,
mrs->prob_ewma);
if (cur_tp_avg > tmp_tp_avg)
mi->max_prob_rate = index;
- max_gpr_group = mg->max_group_prob_rate / MCS_GROUP_RATES;
- max_gpr_idx = mg->max_group_prob_rate % MCS_GROUP_RATES;
- max_gpr_prob = mi->groups[max_gpr_group].rates[max_gpr_idx].prob_ewma;
max_gpr_tp_avg = minstrel_ht_get_tp_avg(mi, max_gpr_group,
max_gpr_idx,
max_gpr_prob);
@@ -431,7 +432,7 @@
} else {
if (mrs->prob_ewma > tmp_prob)
mi->max_prob_rate = index;
- if (mrs->prob_ewma > mg->rates[mg->max_group_prob_rate].prob_ewma)
+ if (mrs->prob_ewma > max_gpr_prob)
mg->max_group_prob_rate = index;
}
}