Re: [PATCH] mac80211: minstrel_ht: fix out-of-bound in minstrel_ht_set_best_prob_rate

[Johannes Berg]

On Fri, 2016-01-29 at 11:35 +0300, Konstantin Khlebnikov wrote:
> Patch fixes this splat
> 
> BUG: KASAN: slab-out-of-bounds in
> minstrel_ht_update_stats.isra.7+0x6e1/0x9e0
> [mac80211] at addr 8800cee640f4 Read of size 4 by task
> swapper/3/0
> 
> Signed-off-by: Konstantin Khlebnikov 
> Link: http://lkml.kernel.org/r/CALYGNiNyJhSaVnE35qS6UCGaSb2Dx1_i5HcRa
> vuox14otz2...@mail.gmail.com
> 

Applied, thanks.

johannes

Re: [PATCH] mac80211: minstrel_ht: fix out-of-bound in minstrel_ht_set_best_prob_rate

[Felix Fietkau]

On 2016-01-29 09:35, Konstantin Khlebnikov wrote:
> Patch fixes this splat
> 
> BUG: KASAN: slab-out-of-bounds in minstrel_ht_update_stats.isra.7+0x6e1/0x9e0
> [mac80211] at addr 8800cee640f4 Read of size 4 by task swapper/3/0
> 
> Signed-off-by: Konstantin Khlebnikov 
> Link: 
> http://lkml.kernel.org/r/calygninyjhsavne35qs6ucgasb2dx1_i5hcravuox14otz2...@mail.gmail.com
Acked-by: Felix Fietkau 

[PATCH] mac80211: minstrel_ht: fix out-of-bound in minstrel_ht_set_best_prob_rate

[Konstantin Khlebnikov]

Patch fixes this splat

BUG: KASAN: slab-out-of-bounds in minstrel_ht_update_stats.isra.7+0x6e1/0x9e0
[mac80211] at addr 8800cee640f4 Read of size 4 by task swapper/3/0

Signed-off-by: Konstantin Khlebnikov 
Link: 
http://lkml.kernel.org/r/calygninyjhsavne35qs6ucgasb2dx1_i5hcravuox14otz2...@mail.gmail.com
---
 net/mac80211/rc80211_minstrel_ht.c |9 +
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/net/mac80211/rc80211_minstrel_ht.c 
b/net/mac80211/rc80211_minstrel_ht.c
index 3928dbd24e25..93bf2b743e20 100644
--- 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 minstrel_ht_sta 
*mi, u16 index)
(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 minstrel_ht_sta *mi, 
u16 index)
} 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;
}
 }