[PATCH wireless-next] wifi: mac80211: reject VHT opmode for unsupported channel widths

[Moon Hee Lee]

VHT operating mode notifications must not be processed when the channel
width is 5 MHz or 10 MHz, as the VHT specification does not support these
narrow widths.

Without validation, a malformed notification using 10 MHz can reach
ieee80211_chan_width_to_rx_bw(), triggering a WARN_ON due to the invalid
width. This issue was reported by syzbot.

Reject these widths early in sta_link_apply_parameters() when
opmode_notif is used.

Reported-by: syzbot+ededba317ddeca8b3f08@xxxxxxxxxxxxxxxxxxxxxxxxx
Closes: https://syzkaller.appspot.com/bug?extid=ededba317ddeca8b3f08
Fixes: 751e7489c1d7 ("wifi: mac80211: expose ieee80211_chan_width_to_rx_bw() to drivers")
Tested-by: syzbot+ededba317ddeca8b3f08@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Moon Hee Lee <moonhee.lee.ca@xxxxxxxxx>
---
 net/mac80211/cfg.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 56540c3701ed..5a6ae093a8bd 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -1981,6 +1981,21 @@ static int sta_link_apply_parameters(struct ieee80211_local *local,
 	ieee80211_sta_init_nss(link_sta);
 
 	if (params->opmode_notif_used) {
+		enum nl80211_chan_width width = link->conf->chanreq.oper.width;
+
+		switch (width) {
+		case NL80211_CHAN_WIDTH_20_NOHT:
+		case NL80211_CHAN_WIDTH_20:
+		case NL80211_CHAN_WIDTH_40:
+		case NL80211_CHAN_WIDTH_80:
+		case NL80211_CHAN_WIDTH_160:
+		case NL80211_CHAN_WIDTH_80P80:
+		case NL80211_CHAN_WIDTH_320:
+			break;
+		default:
+			return -EINVAL;
+		}
+
 		/* returned value is only needed for rc update, but the
 		 * rc isn't initialized here yet, so ignore it
 		 */
-- 
2.43.0