From a7783e585360ee05dfe21d3173dbbe985c94f29e Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Fri, 4 Sep 2026 16:55:01 +0200 Subject: [PATCH] wifi: cfg80211: don't get the radio mask for netdev-less wdevs cfg80211_calculate_bi_data() calls rdev_get_radio_mask() with wdev->netdev, which can be NULL and then crashes in mac80211. To avoid that, invert the order of checks since wdev->netdev is always valid for beaconing interfaces. Assisted-by: LLM Fixes: abb4cfe3661a ("wifi: cfg80211: extend interface combination check for multi-radio") Reported-by: syzbot+abff43d2d045e37c0bb2@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=abff43d2d045e37c0bb2 Link: https://patch.msgid.link/20260904165614.2056a8b7dc91.I7412c5062d8166ad6c81ee7252cec49dea19a60f@changeid Signed-off-by: Johannes Berg --- net/wireless/util.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/net/wireless/util.c b/net/wireless/util.c index 3e584d0ca3e2..408ebb10924f 100644 --- a/net/wireless/util.c +++ b/net/wireless/util.c @@ -2477,16 +2477,15 @@ static void cfg80211_calculate_bi_data(struct wiphy *wiphy, u32 new_beacon_int, if (wdev->valid_links) continue; + wdev_bi = cfg80211_wdev_bi(wdev); + if (!wdev_bi) + continue; + /* skip wdevs not active on the given wiphy radio */ if (radio_idx >= 0 && !(rdev_get_radio_mask(rdev, wdev->netdev) & BIT(radio_idx))) continue; - wdev_bi = cfg80211_wdev_bi(wdev); - - if (!wdev_bi) - continue; - if (!*beacon_int_gcd) { *beacon_int_gcd = wdev_bi; continue;