Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Krzysztof Mazur , Felix Fietkau , Johannes Berg Subject: [ 038/102] mac80211/minstrel: fix NULL pointer dereference issue Date: Thu, 8 Aug 2013 18:57:14 -0700 Message-Id: <20130809015018.780006959@linuxfoundation.org> In-Reply-To: <20130809015010.208118575@linuxfoundation.org> References: <20130809015010.208118575@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Felix Fietkau commit 5c9fc93bc9bc417418fc1b6366833ae6a07b804d upstream. 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 Signed-off-by: Felix Fietkau Signed-off-by: Johannes Berg Signed-off-by: Greg Kroah-Hartman --- net/mac80211/rc80211_minstrel.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/net/mac80211/rc80211_minstrel.c +++ b/net/mac80211/rc80211_minstrel.c @@ -290,7 +290,7 @@ minstrel_get_rate(void *priv, struct iee 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 iee (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;