mac80211: don't WARN on short WMM parameters from AP

commit 05aaa5c97d upstream.

In a very similar spirit to commit c470bdc1aa ("mac80211: don't WARN
on bad WMM parameters from buggy APs"), an AP may not transmit a
fully-formed WMM IE. For example, it may miss or repeat an Access
Category. The above loop won't catch that and will instead leave one of
the four ACs zeroed out. This triggers the following warning in
drv_conf_tx()

  wlan0: invalid CW_min/CW_max: 0/0

and it may leave one of the hardware queues unconfigured. If we detect
such a case, let's just print a warning and fall back to the defaults.

Tested with a hacked version of hostapd, intentionally corrupting the
IEs in hostapd_eid_wmm().

Cc: stable@vger.kernel.org
Signed-off-by: Brian Norris <briannorris@chromium.org>
Link: https://lore.kernel.org/r/20190726224758.210953-1-briannorris@chromium.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Brian Norris
2019-07-26 15:47:58 -07:00
committed by Greg Kroah-Hartman
parent aab77d312d
commit 6c529d4d8b

View File

@@ -1867,6 +1867,16 @@ static bool ieee80211_sta_wmm_params(struct ieee80211_local *local,
}
}
/* WMM specification requires all 4 ACIs. */
for (ac = 0; ac < IEEE80211_NUM_ACS; ac++) {
if (params[ac].cw_min == 0) {
sdata_info(sdata,
"AP has invalid WMM params (missing AC %d), using defaults\n",
ac);
return false;
}
}
for (ac = 0; ac < IEEE80211_NUM_ACS; ac++) {
mlme_dbg(sdata,
"WMM AC=%d acm=%d aifs=%d cWmin=%d cWmax=%d txop=%d uapsd=%d, downgraded=%d\n",