[PATCH 6.18 050/175] wifi: mac80211: dont WARN for connections on invalid channels

Greg Kroah-Hartman
2026-02-09T14:28:16Z

From: Johannes Berg <johannes.berg@intel.com>

[ Upstream commit 99067b58a408a384d2a45c105eb3dce980a862ce ]

It's not clear (to me) how exactly syzbot managed to hit this,
but it seems conceivable that e.g. regulatory changed and has
disabled a channel between scanning (channel is checked to be
usable by cfg80211_get_ies_channel_number) and connecting on
the channel later.

With one scenario that isn't covered elsewhere described above,
the warning isn't good, replace it with a (more informative)
error message.

Reported-by: syzbot+639af5aa411f2581ad38@syzkaller.appspotmail.com
Link: https://patch.msgid.link/20251202102511.5a8fb5184fa3.I961ee41b8f10538a54b8565dbf03ec1696e80e03@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/mac80211/mlme.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index dca47a533392a..8ba199cd38c0f 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -1126,7 +1126,10 @@ ieee80211_determine_chan_mode(struct ieee80211_sub_if_data *sdata,

while (!ieee80211_chandef_usable(sdata, &chanreq->oper,
IEEE80211_CHAN_DISABLED)) {
- if (WARN_ON(chanreq->oper.width == NL80211_CHAN_WIDTH_20_NOHT)) {
+ if (chanreq->oper.width == NL80211_CHAN_WIDTH_20_NOHT) {
+ link_id_info(sdata, link_id,
+ "unusable channel (%d MHz) for connection\n",
+ chanreq->oper.chan->center_freq);
ret = -EINVAL;
goto free;
}
--
2.51.0