Commit 765e98e9 authored Jul 18, 2025 by Johannes Berg

wifi: cfg80211/mac80211: remove wrong scan request n_channels

This (partially) reverts commits
 - 838c7b8f ("wifi: nl80211: Avoid address calculations via out of bounds array indexing")
 - f1d3334d ("wifi: cfg80211: sme: init n_channels before channels[] access")
 - 82bbe02b ("wifi: mac80211: Set n_channels after allocating struct cfg80211_scan_request")

These commits all set the structure to be in an inconsistent
state, setting n_channels to some value before them actually
being filled in. That's fine for what the code does now, but
with the removal of __counted_by() in 444020f4 ("wifi:
cfg80211: remove scan request n_channels counted_by") it's no
longer needed and it does leave a bit of a landmine there
since breaking out of some code to send the scan or something
would leave it wrong.

Remove the now superfluous n_channels settings.

Link: https://patch.msgid.link/20250718103237.59510b2384c5.Ied5ba9c5c49efc008f4491c8ca7a45858a83f064@changeid


Signed-off-by: Johannes Berg <johannes.berg@intel.com>

parent 18b3246d

net/mac80211/main.c

+0 −1

Original line number	Diff line number	Diff line
		@@ -1334,7 +1334,6 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
		GFP_KERNEL);
		if (!local->int_scan_req)
		return -ENOMEM;
		local->int_scan_req->n_channels = channels;

		eth_broadcast_addr(local->int_scan_req->bssid);

net/wireless/nl80211.c

+0 −1

Original line number	Diff line number	Diff line
		@@ -9975,7 +9975,6 @@ static int nl80211_trigger_scan(struct sk_buff skb, struct genl_info info)
		request = kzalloc(size, GFP_KERNEL);
		if (!request)
		return -ENOMEM;
		request->req.n_channels = n_channels;

		if (n_ssids)
		request->req.ssids = (void *)request + ssids_offset;

net/wireless/sme.c

+0 −1

Original line number	Diff line number	Diff line
		@@ -83,7 +83,6 @@ static int cfg80211_conn_scan(struct wireless_dev *wdev)
		if (!request)
		return -ENOMEM;

		request->req.n_channels = n_channels;
		if (wdev->conn->params.channel) {
		enum nl80211_band band = wdev->conn->params.channel->band;
		struct ieee80211_supported_band *sband =