[PATCH 5.6 085/106] mac80211: fix channel switch trigger from unknown mesh peer

[Greg Kroah-Hartman]

From: Tamizh chelvam <tamizhr@xxxxxxxxxxxxxx>

[ Upstream commit 93e2d04a1888668183f3fb48666e90b9b31d29e6 ]

Previously mesh channel switch happens if beacon contains
CSA IE without checking the mesh peer info. Due to that
channel switch happens even if the beacon is not from
its own mesh peer. Fixing that by checking if the CSA
originated from the same mesh network before proceeding
for channel switch.

Signed-off-by: Tamizh chelvam <tamizhr@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/1585403604-29274-1-git-send-email-tamizhr@xxxxxxxxxxxxxx
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 net/mac80211/mesh.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/net/mac80211/mesh.c b/net/mac80211/mesh.c
index d09b3c789314d..36978a0e50001 100644
--- a/net/mac80211/mesh.c
+++ b/net/mac80211/mesh.c
@@ -1257,15 +1257,15 @@ static void ieee80211_mesh_rx_bcn_presp(struct ieee80211_sub_if_data *sdata,
 		    sdata->u.mesh.mshcfg.rssi_threshold < rx_status->signal)
 			mesh_neighbour_update(sdata, mgmt->sa, &elems,
 					      rx_status);
+
+		if (ifmsh->csa_role != IEEE80211_MESH_CSA_ROLE_INIT &&
+		    !sdata->vif.csa_active)
+			ieee80211_mesh_process_chnswitch(sdata, &elems, true);
 	}
 
 	if (ifmsh->sync_ops)
 		ifmsh->sync_ops->rx_bcn_presp(sdata,
 			stype, mgmt, &elems, rx_status);
-
-	if (ifmsh->csa_role != IEEE80211_MESH_CSA_ROLE_INIT &&
-	    !sdata->vif.csa_active)
-		ieee80211_mesh_process_chnswitch(sdata, &elems, true);
 }
 
 int ieee80211_mesh_finish_csa(struct ieee80211_sub_if_data *sdata)
@@ -1373,6 +1373,9 @@ static void mesh_rx_csa_frame(struct ieee80211_sub_if_data *sdata,
 	ieee802_11_parse_elems(pos, len - baselen, true, &elems,
 			       mgmt->bssid, NULL);
 
+	if (!mesh_matches_local(sdata, &elems))
+		return;
+
 	ifmsh->chsw_ttl = elems.mesh_chansw_params_ie->mesh_ttl;
 	if (!--ifmsh->chsw_ttl)
 		fwd_csa = false;
-- 
2.20.1