From 5c9fc93bc9bc417418fc1b6366833ae6a07b804d Mon Sep 17 00:00:00 2001 From: Felix Fietkau Date: Mon, 15 Jul 2013 14:35:06 +0200 Subject: [PATCH] mac80211/minstrel: fix NULL pointer dereference issue When priv_sta == NULL, mi->prev_sample is dereferenced too early. Move the assignment further down, after the rate_control_send_low call. Reported-by: Krzysztof Mazur Cc: stable@vger.kernel.org # 3.10 Signed-off-by: Felix Fietkau Signed-off-by: Johannes Berg --- net/mac80211/rc80211_minstrel.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/mac80211/rc80211_minstrel.c b/net/mac80211/rc80211_minstrel.c index ac7ef54..e6512e2 100644 --- a/net/mac80211/rc80211_minstrel.c +++ b/net/mac80211/rc80211_minstrel.c @@ -290,7 +290,7 @@ minstrel_get_rate(void *priv, struct ieee80211_sta *sta, struct minstrel_rate *msr, *mr; unsigned int ndx; bool mrr_capable; - bool prev_sample = mi->prev_sample; + bool prev_sample; int delta; int sampling_ratio; @@ -314,6 +314,7 @@ minstrel_get_rate(void *priv, struct ieee80211_sta *sta, (mi->sample_count + mi->sample_deferred / 2); /* delta < 0: no sampling required */ + prev_sample = mi->prev_sample; mi->prev_sample = false; if (delta < 0 || (!mrr_capable && prev_sample)) return; -- 2.7.4