wifi: cfg80211: Set correct chandef when starting CAC

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

Reported-by: Kretschmer Mathias <mathias.kretschmer@fit.fraunhofer.de>
Signed-off-by: Issam Hamdi <ih@simonwunderlich.de>
Link: https://patch.msgid.link/20240816142418.3381951-1-ih@simonwunderlich.de
[shorten subject, remove OCB, reorder cases to match previous list]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 7397a372c78eb7b79a1348311a2d26a119c35093..b368e23847ddb1aeaf39c4a0af1bc68fa4571889 100644 (file)
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -10143,7 +10143,20 @@ 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_AP:
+               case NL80211_IFTYPE_P2P_GO:
+                       wdev->links[0].ap.chandef = chandef;
+                       break;
+               case NL80211_IFTYPE_ADHOC:
+                       wdev->u.ibss.chandef = chandef;
+                       break;
+               case NL80211_IFTYPE_MESH_POINT:
+                       wdev->u.mesh.chandef = chandef;
+                       break;
+               default:
+                       break;
+               }
                wdev->cac_started = true;
                wdev->cac_start_time = jiffies;
                wdev->cac_time_ms = cac_time_ms;