Return-path: Received: from nbd.name ([46.4.11.11]:49183 "EHLO nbd.name" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753533Ab1CYOar (ORCPT ); Fri, 25 Mar 2011 10:30:47 -0400 From: Felix Fietkau To: linux-wireless@vger.kernel.org Cc: linville@tuxdriver.com, johannes@sipsolutions.net Subject: [PATCH] mac80211: fix a crash in minstrel_ht in HT mode with no supported MCS rates Date: Fri, 25 Mar 2011 15:30:38 +0100 Message-Id: <1301063438-20460-1-git-send-email-nbd@openwrt.org> Sender: linux-wireless-owner@vger.kernel.org List-ID: When a client connects in HT mode but does not provide any valid MCS rates, the function that finds the next sample rate gets stuck in an infinite loop. Fix this by falling back to legacy rates if no usable MCS rates are found. Signed-off-by: Felix Fietkau Cc: stable@kernel.org --- net/mac80211/rc80211_minstrel_ht.c | 25 ++++++++++++++++++------- 1 files changed, 18 insertions(+), 7 deletions(-) diff --git a/net/mac80211/rc80211_minstrel_ht.c b/net/mac80211/rc80211_minstrel_ht.c index 8212a8b..dbdebed 100644 --- a/net/mac80211/rc80211_minstrel_ht.c +++ b/net/mac80211/rc80211_minstrel_ht.c @@ -659,18 +659,14 @@ minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband, struct ieee80211_mcs_info *mcs = &sta->ht_cap.mcs; struct ieee80211_local *local = hw_to_local(mp->hw); u16 sta_cap = sta->ht_cap.cap; + int n_supported = 0; int ack_dur; int stbc; int i; /* fall back to the old minstrel for legacy stations */ - if (!sta->ht_cap.ht_supported) { - msp->is_ht = false; - memset(&msp->legacy, 0, sizeof(msp->legacy)); - msp->legacy.r = msp->ratelist; - msp->legacy.sample_table = msp->sample_table; - return mac80211_minstrel.rate_init(priv, sband, sta, &msp->legacy); - } + if (!sta->ht_cap.ht_supported) + goto use_legacy; BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) != MINSTREL_MAX_STREAMS * MINSTREL_STREAM_GROUPS); @@ -725,7 +721,22 @@ minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband, mi->groups[i].supported = mcs->rx_mask[minstrel_mcs_groups[i].streams - 1]; + + if (mi->groups[i].supported) + n_supported++; } + + if (!n_supported) + goto use_legacy; + + return; + +use_legacy: + msp->is_ht = false; + memset(&msp->legacy, 0, sizeof(msp->legacy)); + msp->legacy.r = msp->ratelist; + msp->legacy.sample_table = msp->sample_table; + return mac80211_minstrel.rate_init(priv, sband, sta, &msp->legacy); } static void -- 1.7.3.2