Update pending connect radio work BSS pointer on scan update

It is possible for scan result processing or BSS entry removal to occur
while there is a pending connect or sme-connect radio work with a
previously selected BSS entry. The BSS pointer was previously verified
to be valid, i.e., still point to a BSS entry, at the time the actual
connection operation is started. However, that BSS entry could have
changed to point to another BSS if the old BSS entry was either removed
or reallocated and a new BSS entry was added at the same location in
memory. This could result in the connection attempt failing to configure
parameters properly due to different BSS information (e.g., different
BSSID).

Fix this by updated the pending connect radio work data on BSS entry
updates similarly to how the last_scan_res array was updated. If the
selected BSS entry is removed, this will still result in a failed
connection, but reallocated BSS entry is now followed properly and used
when the connection work starts.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>

wpa_supplicant/bss.c

@@ -174,6 +174,31 @@ static void wpa_bss_anqp_free(struct wpa_bss_anqp *anqp)
 }
 
 
+static void wpa_bss_update_pending_connect(struct wpa_supplicant *wpa_s,
+					   struct wpa_bss *old_bss,
+					   struct wpa_bss *new_bss)
+{
+	struct wpa_radio_work *work;
+	struct wpa_connect_work *cwork;
+
+	work = radio_work_pending(wpa_s, "sme-connect");
+	if (!work)
+		work = radio_work_pending(wpa_s, "connect");
+	if (!work)
+		return;
+
+	cwork = work->ctx;
+	if (cwork->bss != old_bss)
+		return;
+
+	wpa_printf(MSG_DEBUG,
+		   "Update BSS pointer for the pending connect radio work");
+	cwork->bss = new_bss;
+	if (!new_bss)
+		cwork->bss_removed = 1;
+}
+
+
 static void wpa_bss_remove(struct wpa_supplicant *wpa_s, struct wpa_bss *bss,
 			   const char *reason)
 {
@@ -190,6 +215,7 @@ static void wpa_bss_remove(struct wpa_supplicant *wpa_s, struct wpa_bss *bss,
 			}
 		}
 	}
+	wpa_bss_update_pending_connect(wpa_s, bss, NULL);
 	dl_list_del(&bss->list);
 	dl_list_del(&bss->list_id);
 	wpa_s->num_bss--;
@@ -543,6 +569,7 @@ wpa_bss_update(struct wpa_supplicant *wpa_s, struct wpa_bss *bss,
 			}
 			if (wpa_s->current_bss == bss)
 				wpa_s->current_bss = nbss;
+			wpa_bss_update_pending_connect(wpa_s, bss, nbss);
 			bss = nbss;
 			os_memcpy(bss + 1, res + 1,
 				  res->ie_len + res->beacon_ie_len);

wpa_supplicant/sme.c

@@ -497,7 +497,8 @@ static void sme_auth_start_cb(struct wpa_radio_work *work, int deinit)
 
 	wpa_s->connect_work = work;
 
-	if (!wpas_valid_bss_ssid(wpa_s, cwork->bss, cwork->ssid)) {
+	if (cwork->bss_removed ||
+	    !wpas_valid_bss_ssid(wpa_s, cwork->bss, cwork->ssid)) {
 		wpa_dbg(wpa_s, MSG_DEBUG, "SME: BSS/SSID entry for authentication not valid anymore - drop connection attempt");
 		wpas_connect_work_done(wpa_s);
 		return;

wpa_supplicant/wpa_supplicant.c

@@ -1602,7 +1602,7 @@ static void wpas_start_assoc_cb(struct wpa_radio_work *work, int deinit)
 
 	wpa_s->connect_work = work;
 
-	if (!wpas_valid_bss_ssid(wpa_s, bss, ssid)) {
+	if (cwork->bss_removed || !wpas_valid_bss_ssid(wpa_s, bss, ssid)) {
 		wpa_dbg(wpa_s, MSG_DEBUG, "BSS/SSID entry for association not valid anymore - drop connection attempt");
 		wpas_connect_work_done(wpa_s);
 		return;
@@ -3608,17 +3608,18 @@ void radio_work_done(struct wpa_radio_work *work)
 }
 
 
-int radio_work_pending(struct wpa_supplicant *wpa_s, const char *type)
+struct wpa_radio_work *
+radio_work_pending(struct wpa_supplicant *wpa_s, const char *type)
 {
 	struct wpa_radio_work *work;
 	struct wpa_radio *radio = wpa_s->radio;
 
 	dl_list_for_each(work, &radio->work, struct wpa_radio_work, list) {
 		if (work->wpa_s == wpa_s && os_strcmp(work->type, type) == 0)
-			return 1;
+			return work;
 	}
 
-	return 0;
+	return NULL;
 }
 
 

wpa_supplicant/wpa_supplicant_i.h

@@ -321,10 +321,12 @@ void radio_work_done(struct wpa_radio_work *work);
 void radio_remove_works(struct wpa_supplicant *wpa_s,
 			const char *type, int remove_all);
 void radio_work_check_next(struct wpa_supplicant *wpa_s);
-int radio_work_pending(struct wpa_supplicant *wpa_s, const char *type);
+struct wpa_radio_work *
+radio_work_pending(struct wpa_supplicant *wpa_s, const char *type);
 
 struct wpa_connect_work {
 	unsigned int sme:1;
+	unsigned int bss_removed:1;
 	struct wpa_bss *bss;
 	struct wpa_ssid *ssid;
 };