[PATCH] cfg80211: Set the channel definition for the different Wi-Fi modes when starting CAC

[Issam Hamdi <ih@xxxxxxxxxxxxxxxxxx>]

When starting CAC in a mode other than AP mode, it return a
"WARNING: CPU: 0 PID: 63 at cfg80211_chandef_dfs_usable+0x20/0xaf [cfg80211]"
caused by the chandef.chan being null at the end of CAC.

Solution: Ensure the channel definition is set for the different modes
when starting CAC to avoid getting a NULL 'chan' at the end of CAC.

 Call Trace:
  ? show_regs.part.0+0x14/0x16
  ? __warn+0x67/0xc0
  ? cfg80211_chandef_dfs_usable+0x20/0xaf [cfg80211]
  ? report_bug+0xa7/0x130
  ? exc_overflow+0x30/0x30
  ? handle_bug+0x27/0x50
  ? exc_invalid_op+0x18/0x60
  ? handle_exception+0xf6/0xf6
  ? exc_overflow+0x30/0x30
  ? cfg80211_chandef_dfs_usable+0x20/0xaf [cfg80211]
  ? exc_overflow+0x30/0x30
  ? cfg80211_chandef_dfs_usable+0x20/0xaf [cfg80211]
  ? regulatory_propagate_dfs_state.cold+0x1b/0x4c [cfg80211]
  ? cfg80211_propagate_cac_done_wk+0x1a/0x30 [cfg80211]
  ? process_one_work+0x165/0x280
  ? worker_thread+0x120/0x3f0
  ? kthread+0xc2/0xf0
  ? process_one_work+0x280/0x280
  ? kthread_complete_and_exit+0x20/0x20
  ? ret_from_fork+0x19/0x24

Signed-off-by: Issam Hamdi <ih@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Kretschmer Mathias <mathias.kretschmer@xxxxxxxxxxxxxxxxx>
---
 net/wireless/nl80211.c | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 7397a372c78e..36ae2594753e 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -10143,7 +10143,23 @@ static int nl80211_start_radar_detection(struct sk_buff *skb,
 
 	err = rdev_start_radar_detection(rdev, dev, &chandef, cac_time_ms);
 	if (!err) {
-		wdev->links[0].ap.chandef = chandef;
+		switch (wdev->iftype) {
+		case NL80211_IFTYPE_MESH_POINT:
+			wdev->u.mesh.chandef = chandef;
+			break;
+		case NL80211_IFTYPE_ADHOC:
+			wdev->u.ibss.chandef = chandef;
+			break;
+		case NL80211_IFTYPE_OCB:
+			wdev->u.ocb.chandef = chandef;
+			break;
+		case NL80211_IFTYPE_AP:
+		case NL80211_IFTYPE_P2P_GO:
+			wdev->links[0].ap.chandef = chandef;
+			break;
+		default:
+			break;
+		}
 		wdev->cac_started = true;
 		wdev->cac_start_time = jiffies;
 		wdev->cac_time_ms = cac_time_ms;

base-commit: cc32e9fb380d8afdbf3486d7063d5520bfb0f071
-- 
2.39.2