From: Felix Fietkau Date: Tue, 18 Nov 2014 22:20:50 +0000 (+0000) Subject: mac80211: fix a crash bug in minstrel_ht X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=49aca2431c7432aa976d38a2b342d50602c68c60;p=librecmc%2Flibrecmc.git mac80211: fix a crash bug in minstrel_ht Signed-off-by: Felix Fietkau SVN-Revision: 43298 --- diff --git a/package/kernel/mac80211/patches/319-mac80211-minstrel_ht-fix-a-crash-in-rate-sorting.patch b/package/kernel/mac80211/patches/319-mac80211-minstrel_ht-fix-a-crash-in-rate-sorting.patch new file mode 100644 index 0000000000..784a973e0e --- /dev/null +++ b/package/kernel/mac80211/patches/319-mac80211-minstrel_ht-fix-a-crash-in-rate-sorting.patch @@ -0,0 +1,47 @@ +From: Felix Fietkau +Date: Tue, 18 Nov 2014 21:43:25 +0100 +Subject: [PATCH] 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 +Reported-by: Jouni Malinen +Signed-off-by: Felix Fietkau +--- + +--- a/net/mac80211/rc80211_minstrel_ht.c ++++ b/net/mac80211/rc80211_minstrel_ht.c +@@ -394,19 +394,16 @@ minstrel_ht_sort_best_tp_rates(struct mi + 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) *