From 4dc217df68a17a57f8464c74c1b4785e40bddf77 Mon Sep 17 00:00:00 2001 From: Felix Fietkau Date: Fri, 25 Mar 2011 15:30:38 +0100 Subject: [PATCH] mac80211: fix a crash in minstrel_ht in HT mode with no supported MCS rates 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 Signed-off-by: John W. Linville --- net/mac80211/rc80211_minstrel_ht.c | 25 ++++++++++++++++++------- 1 file changed, 18 insertions(+), 7 deletions(-) diff --git a/net/mac80211/rc80211_minstrel_ht.c b/net/mac80211/rc80211_minstrel_ht.c index 8212a8bebf06..dbdebeda097f 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 -- 2.20.1