mac80211: fix channel selection bug (3d9646d0) · Commits · 戴 / test

When trying to connect to an AP that advertises HT but not VHT, the mac80211 code erroneously uses the configuration from the AP as is instead of checking it against regulatory and local capabilities. This can lead to using an invalid or even inexistent channel (like 11/HT40+). Additionally, the return flags from downgrading must be ORed together, to collect them from all of the downgrades. Also clarify the message. Signed-off-by:

Johannes Berg <johannes.berg@intel.com>

net/mac80211/mlme.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -3400,6 +3400,7 @@ ieee80211_determine_chantype(struct ieee80211_sub_if_data *sdata,

		ret = 0;

		out:
		while (!cfg80211_chandef_usable(sdata->local->hw.wiphy, chandef,
		IEEE80211_CHAN_DISABLED)) {
		if (WARN_ON(chandef->width == NL80211_CHAN_WIDTH_20_NOHT)) {
		@@ -3408,14 +3409,13 @@ ieee80211_determine_chantype(struct ieee80211_sub_if_data *sdata,
		goto out;
		}

		ret = chandef_downgrade(chandef);
		ret \|= chandef_downgrade(chandef);
		}

		if (chandef->width != vht_chandef.width)
		sdata_info(sdata,
		"local regulatory prevented using AP HT/VHT configuration, downgraded\n");
		"capabilities/regulatory prevented using AP HT/VHT configuration, downgraded\n");

		out:
		WARN_ON_ONCE(!cfg80211_chandef_valid(chandef));
		return ret;
		}

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