mac80211: fix an out of bounds access issue in minstrel_ht

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

SVN-Revision: 48550
This commit is contained in:
Felix Fietkau 2016-01-29 14:23:23 +00:00
parent 6fd5449198
commit a6fe27a59a

View File

@ -0,0 +1,45 @@
From: Konstantin Khlebnikov <koct9i@gmail.com>
Date: Fri, 29 Jan 2016 11:35:12 +0300
Subject: [PATCH] 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
---
--- a/net/mac80211/rc80211_minstrel_ht.c
+++ b/net/mac80211/rc80211_minstrel_ht.c
@@ -414,15 +414,16 @@ minstrel_ht_set_best_prob_rate(struct mi
(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 @@ minstrel_ht_set_best_prob_rate(struct mi
} 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;
}
}