[PATCH] mac80211: fix invalid read in minstrel_sort_best_tp_rates()
DORMANTno replies
From: Adrien Schildknecht <hidden>
Date: 2015-07-28 08:30:58
Also in:
linux-wireless, lkml
Subsystem:
mac80211, the rest · Maintainers:
Johannes Berg, Linus Torvalds
At the last iteration of the loop, j may equal zero and thus tp_list[j - 1] causes an invalid read. Changed the logic of the loop so that j - 1 is always >= 0. Signed-off-by: Adrien Schildknecht <redacted> --- net/mac80211/rc80211_minstrel.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/net/mac80211/rc80211_minstrel.c b/net/mac80211/rc80211_minstrel.c
index 247552a..3ece7d1 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)
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2.4.6