mac80211: handle deauthentication/disassociation from TDLS peer

When receiving a deauthentication/disassociation frame from a TDLS
peer, a station should not disconnect the current AP, but only
disable the current TDLS link if it's enabled.

Without this change, a TDLS issue can be reproduced by following the
steps as below:

1. STA-1 and STA-2 are connected to AP, bidirection traffic is running
   between STA-1 and STA-2.
2. Set up TDLS link between STA-1 and STA-2, stay for a while, then
   teardown TDLS link.
3. Repeat step #2 and monitor the connection between STA and AP.

During the test, one STA may send a deauthentication/disassociation
frame to another, after TDLS teardown, with reason code 6/7, which
means: Class 2/3 frame received from nonassociated STA.

On receive this frame, the receiver STA will disconnect the current
AP and then reconnect. It's not a expected behavior, purpose of this
frame should be disabling the TDLS link, not the link with AP.

Cc: stable@vger.kernel.org
Signed-off-by: Yu Wang <yyuwang@codeaurora.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 11 insertions, 1 deletions

diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index b7a9fe3d5fcb..383b0df100e4 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -2963,7 +2963,7 @@ static void ieee80211_rx_mgmt_auth(struct ieee80211_sub_if_data *sdata,
 #define case_WLAN(type) \
         case WLAN_REASON_##type: return #type
 
-static const char *ieee80211_get_reason_code_string(u16 reason_code)
+const char *ieee80211_get_reason_code_string(u16 reason_code)
 {
         switch (reason_code) {
         case_WLAN(UNSPECIFIED);
@@ -3028,6 +3028,11 @@ static void ieee80211_rx_mgmt_deauth(struct ieee80211_sub_if_data *sdata,
         if (len < 24 + 2)
                 return;
 
+        if (!ether_addr_equal(mgmt->bssid, mgmt->sa)) {
+                ieee80211_tdls_handle_disconnect(sdata, mgmt->sa, reason_code);
+                return;
+        }
+
         if (ifmgd->associated &&
             ether_addr_equal(mgmt->bssid, ifmgd->associated->bssid)) {
                 const u8 *bssid = ifmgd->associated->bssid;
@@ -3077,6 +3082,11 @@ static void ieee80211_rx_mgmt_disassoc(struct ieee80211_sub_if_data *sdata,
 
         reason_code = le16_to_cpu(mgmt->u.disassoc.reason_code);
 
+        if (!ether_addr_equal(mgmt->bssid, mgmt->sa)) {
+                ieee80211_tdls_handle_disconnect(sdata, mgmt->sa, reason_code);
+                return;
+        }
+
         sdata_info(sdata, "disassociated from %pM (Reason: %u=%s)\n",
                    mgmt->sa, reason_code,
                    ieee80211_get_reason_code_string(reason_code));