[PATCH 4.9 17/61] mac80211: dont WARN on bad WMM parameters from buggy APs

From: Greg Kroah-Hartman
Date: Thu Dec 20 2018 - 04:24:01 EST

4.9-stable review patch. If anyone has any objections, please let me know.


[ Upstream commit c470bdc1aaf36669e04ba65faf1092b2d1c6cabe ]

Apparently, some APs are buggy enough to send a zeroed
WMM IE. Don't WARN on this since this is not caused by a bug
on the client's system.

This aligns the condition of the WARNING in drv_conf_tx
with the validity check in ieee80211_sta_wmm_params.
We will now pick the default values whenever we get
a zeroed WMM IE.

This has been reported here:

Fixes: f409079bb678 ("mac80211: sanity check CW_min/CW_max towards driver")
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@xxxxxxxxx>
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
net/mac80211/mlme.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 39451c84c785..7811650e76c4 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -1867,7 +1867,8 @@ static bool ieee80211_sta_wmm_params(struct ieee80211_local *local,
params[ac].acm = acm;
params[ac].uapsd = uapsd;

- if (params[ac].cw_min > params[ac].cw_max) {
+ if (params->cw_min == 0 ||
+ params[ac].cw_min > params[ac].cw_max) {
"AP has invalid WMM params (CWmin/max=%d/%d for ACI %d), using defaults\n",
params[ac].cw_min, params[ac].cw_max, aci);