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| author |   Felix Fietkau <nbd@openwrt.org> | 2014-11-18 22:35:31 +0100 |
|---|---|---|
| committer |   Johannes Berg <johannes.berg@intel.com> | 2014-11-18 22:39:16 +0100 |
| commit | 280ba51d60be6f4ca3347eaa60783314f38df72e (patch) | |
| tree | 4b6f66ce8187b59e755f02f14ffd5d488b6084df /net/mac80211/rc80211_minstrel_ht.c | |
| parent | mac80211: Fix regression that triggers a kernel BUG with CCMP (diff) | |
| download | linux-dev-280ba51d60be6f4ca3347eaa60783314f38df72e.tar.xz linux-dev-280ba51d60be6f4ca3347eaa60783314f38df72e.zip | |
mac80211: minstrel_ht: fix a crash in rate sorting
The commit 5935839ad73583781b8bbe8d91412f6826e218a4
"mac80211: improve minstrel_ht rate sorting by throughput & probability"
introduced a crash on rate sorting that occurs when the rate added to
the sorting array is faster than all the previous rates. Due to an
off-by-one error, it reads the rate index from tp_list[-1], which
contains uninitialized stack garbage, and then uses the resulting index
for accessing the group rate stats, leading to a crash if the garbage
value is big enough.
Cc: Thomas Huehn <thomas@net.t-labs.tu-berlin.de>
Reported-by: Jouni Malinen <j@w1.fi>
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Diffstat (limited to 'net/mac80211/rc80211_minstrel_ht.c')
| -rw-r--r-- | net/mac80211/rc80211_minstrel_ht.c | 15 |
1 files changed, 6 insertions, 9 deletions
diff --git a/net/mac80211/rc80211_minstrel_ht.c b/net/mac80211/rc80211_minstrel_ht.c index df90ce2db00c..408fd8ab4eef 100644 --- a/net/mac80211/rc80211_minstrel_ht.c +++ b/net/mac80211/rc80211_minstrel_ht.c @@ -252,19 +252,16 @@ minstrel_ht_sort_best_tp_rates(struct minstrel_ht_sta *mi, u8 index, cur_thr = mi->groups[cur_group].rates[cur_idx].cur_tp; cur_prob = mi->groups[cur_group].rates[cur_idx].probability; - tmp_group = tp_list[j - 1] / MCS_GROUP_RATES; - tmp_idx = tp_list[j - 1] % MCS_GROUP_RATES; - tmp_thr = mi->groups[tmp_group].rates[tmp_idx].cur_tp; - tmp_prob = mi->groups[tmp_group].rates[tmp_idx].probability; - - while (j > 0 && (cur_thr > tmp_thr || - (cur_thr == tmp_thr && cur_prob > tmp_prob))) { - j--; + do { tmp_group = tp_list[j - 1] / MCS_GROUP_RATES; tmp_idx = tp_list[j - 1] % MCS_GROUP_RATES; tmp_thr = mi->groups[tmp_group].rates[tmp_idx].cur_tp; tmp_prob = mi->groups[tmp_group].rates[tmp_idx].probability; - } + if (cur_thr < tmp_thr || + (cur_thr == tmp_thr && cur_prob <= tmp_prob)) + break; + j--; + } while (j > 0); if (j < MAX_THR_RATES - 1) { memmove(&tp_list[j + 1], &tp_list[j], (sizeof(*tp_list) * |