[PATCH wireless 1/8] wifi: cfg80211: don't get the radio mask for netdev-less wdevs

From: Johannes Berg <redacted>

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
Signed-off-by: Johannes Berg <redacted>
---
 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;

-- 
2.55.0