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| author | Adrien Schildknecht <adrien+dev@schischi.me> | 2015-07-28 10:30:16 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-09-13 09:07:48 -0700 |
| commit | 82cb8352e372319b2fc57bd6ed34c726a37fe24b (patch) | |
| tree | 7b0f98812c32c2e76fe99413125027aa4504d6ef | |
| parent | 360c2a1448754b76fbf742b6270f5da1d4db3700 (diff) | |
| download | lwn-82cb8352e372319b2fc57bd6ed34c726a37fe24b.tar.gz lwn-82cb8352e372319b2fc57bd6ed34c726a37fe24b.zip | |
mac80211: fix invalid read in minstrel_sort_best_tp_rates()
commit f5eeb5fa191fd7b634cbc4883ac58f3b2184dbc5 upstream.
At the last iteration of the loop, j may equal zero and thus
tp_list[j - 1] causes an invalid read.
Change the logic of the loop so that j - 1 is always >= 0.
Signed-off-by: Adrien Schildknecht <adrien+dev@schischi.me>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | net/mac80211/rc80211_minstrel.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/net/mac80211/rc80211_minstrel.c b/net/mac80211/rc80211_minstrel.c index 247552a7f6c2..3ece7d1034c8 100644 --- a/net/mac80211/rc80211_minstrel.c +++ b/net/mac80211/rc80211_minstrel.c @@ -92,14 +92,15 @@ int minstrel_get_tp_avg(struct minstrel_rate *mr, int prob_ewma) static inline void minstrel_sort_best_tp_rates(struct minstrel_sta_info *mi, int i, u8 *tp_list) { - int j = MAX_THR_RATES; - struct minstrel_rate_stats *tmp_mrs = &mi->r[j - 1].stats; + int j; + struct minstrel_rate_stats *tmp_mrs; struct minstrel_rate_stats *cur_mrs = &mi->r[i].stats; - while (j > 0 && (minstrel_get_tp_avg(&mi->r[i], cur_mrs->prob_ewma) > - minstrel_get_tp_avg(&mi->r[tp_list[j - 1]], tmp_mrs->prob_ewma))) { - j--; + for (j = MAX_THR_RATES; j > 0; --j) { tmp_mrs = &mi->r[tp_list[j - 1]].stats; + if (minstrel_get_tp_avg(&mi->r[i], cur_mrs->prob_ewma) <= + minstrel_get_tp_avg(&mi->r[tp_list[j - 1]], tmp_mrs->prob_ewma)) + break; } if (j < MAX_THR_RATES - 1) |