Flush pending control interface message for an interface to be removed

wpa_supplicant_ctrl_iface_deinit() was executed only if the
per-interface control interface initialization had been completed. This
is not the case if driver initialization fails and that could result in
leaving behind references to the freed wpa_s instance in a corner case
where control interface messages ended up getting queued.

Fix this by calling wpa_supplicant_ctrl_iface_deinit() in all cases to
cancel the potential eloop timeout for wpas_ctrl_msg_queue_timeout with
the reference to the wpa_s pointer. In addition, flush any pending
message from the global queue for this interface since such a message
cannot be of use after this and there is no need to leave them in the
queue until the global control interface gets deinitialized.

Signed-off-by: Jouni Malinen <jouni@codeaurora.org>

wpa_supplicant/ctrl_iface.h

@@ -70,14 +70,17 @@ wpa_supplicant_ctrl_iface_init(struct wpa_supplicant *wpa_s);
 
 /**
  * wpa_supplicant_ctrl_iface_deinit - Deinitialize control interface
+ * @wpa_s: Pointer to wpa_supplicant data
  * @priv: Pointer to private data from wpa_supplicant_ctrl_iface_init()
  *
  * Deinitialize the control interface that was initialized with
- * wpa_supplicant_ctrl_iface_init().
+ * wpa_supplicant_ctrl_iface_init() and any data related to the wpa_s instance.
+ * @priv may be %NULL if the control interface has not yet been initialized.
  *
  * Required to be implemented in each control interface backend.
  */
-void wpa_supplicant_ctrl_iface_deinit(struct ctrl_iface_priv *priv);
+void wpa_supplicant_ctrl_iface_deinit(struct wpa_supplicant *wpa_s,
+				      struct ctrl_iface_priv *priv);
 
 /**
  * wpa_supplicant_ctrl_iface_wait - Wait for ctrl_iface monitor
@@ -128,7 +131,8 @@ wpa_supplicant_ctrl_iface_init(struct wpa_supplicant *wpa_s)
 }
 
 static inline void
-wpa_supplicant_ctrl_iface_deinit(struct ctrl_iface_priv *priv)
+wpa_supplicant_ctrl_iface_deinit(struct wpa_supplicant *wpa_s,
+				 struct ctrl_iface_priv *priv)
 {
 }
 

wpa_supplicant/ctrl_iface_named_pipe.c

@@ -462,8 +462,11 @@ wpa_supplicant_ctrl_iface_init(struct wpa_supplicant *wpa_s)
 }
 
 
-void wpa_supplicant_ctrl_iface_deinit(struct ctrl_iface_priv *priv)
+void wpa_supplicant_ctrl_iface_deinit(struct wpa_supplicant *wpa_s,
+				      struct ctrl_iface_priv *priv)
 {
+	if (!priv)
+		return;
 	while (priv->ctrl_dst)
 		ctrl_close_pipe(priv->ctrl_dst);
 	if (priv->sec_attr_set)

wpa_supplicant/ctrl_iface_udp.c

@@ -490,8 +490,12 @@ fail:
 }
 
 
-void wpa_supplicant_ctrl_iface_deinit(struct ctrl_iface_priv *priv)
+void wpa_supplicant_ctrl_iface_deinit(struct wpa_supplicant *wpa_s,
+				      struct ctrl_iface_priv *priv)
 {
+	if (!priv)
+		return;
+
 	if (priv->sock > -1) {
 		eloop_unregister_read_sock(priv->sock);
 		if (priv->ctrl_dst) {

wpa_supplicant/ctrl_iface_unix.c

@@ -800,12 +800,52 @@ static int wpas_ctrl_iface_reinit(struct wpa_supplicant *wpa_s,
 }
 
 
-void wpa_supplicant_ctrl_iface_deinit(struct ctrl_iface_priv *priv)
+static void
+wpas_global_ctrl_iface_flush_queued_msg(struct wpa_global *global,
+					struct wpa_supplicant *wpa_s)
+{
+	struct ctrl_iface_global_priv *gpriv;
+	struct ctrl_iface_msg *msg, *prev_msg;
+	unsigned int count = 0;
+
+	if (!global || !global->ctrl_iface)
+		return;
+
+	gpriv = global->ctrl_iface;
+	dl_list_for_each_safe(msg, prev_msg, &gpriv->msg_queue,
+			      struct ctrl_iface_msg, list) {
+		if (msg->wpa_s == wpa_s) {
+			count++;
+			dl_list_del(&msg->list);
+			os_free(msg);
+		}
+	}
+
+	if (count) {
+		wpa_printf(MSG_DEBUG,
+			   "CTRL: Dropped %u pending message(s) for interface that is being removed",
+			count);
+	}
+}
+
+
+void wpa_supplicant_ctrl_iface_deinit(struct wpa_supplicant *wpa_s,
+				      struct ctrl_iface_priv *priv)
 {
 	struct wpa_ctrl_dst *dst, *prev;
 	struct ctrl_iface_msg *msg, *prev_msg;
 	struct ctrl_iface_global_priv *gpriv;
 
+	if (!priv) {
+		/* Control interface has not yet been initialized, so there is
+		 * nothing to deinitialize here. However, there might be a
+		 * pending message for this interface, so get rid of any such
+		 * entry before completing interface removal. */
+		wpas_global_ctrl_iface_flush_queued_msg(wpa_s->global, wpa_s);
+		eloop_cancel_timeout(wpas_ctrl_msg_queue_timeout, wpa_s, NULL);
+		return;
+	}
+
 	if (priv->sock > -1) {
 		char *fname;
 		char *buf, *dir = NULL;
@@ -877,6 +917,7 @@ free_dst:
 			}
 		}
 	}
+	wpas_global_ctrl_iface_flush_queued_msg(wpa_s->global, wpa_s);
 	eloop_cancel_timeout(wpas_ctrl_msg_queue_timeout, priv->wpa_s, NULL);
 	os_free(priv);
 }

wpa_supplicant/eapol_test.c

@@ -674,10 +674,8 @@ static void test_eapol_clean(struct eapol_test_data *e,
 	os_free(e->radius_conf);
 	e->radius_conf = NULL;
 	scard_deinit(wpa_s->scard);
-	if (wpa_s->ctrl_iface) {
+	wpa_supplicant_ctrl_iface_deinit(wpa_s, wpa_s->ctrl_iface);
-		wpa_supplicant_ctrl_iface_deinit(wpa_s->ctrl_iface);
 	wpa_s->ctrl_iface = NULL;
-	}
 
 	ext_password_deinit(wpa_s->ext_pw);
 	wpa_s->ext_pw = NULL;

wpa_supplicant/preauth_test.c

@@ -193,10 +193,8 @@ static void test_eapol_clean(struct wpa_supplicant *wpa_s)
 	pmksa_candidate_free(wpa_s->wpa);
 	wpa_sm_deinit(wpa_s->wpa);
 	scard_deinit(wpa_s->scard);
-	if (wpa_s->ctrl_iface) {
+	wpa_supplicant_ctrl_iface_deinit(wpa_s, wpa_s->ctrl_iface);
-		wpa_supplicant_ctrl_iface_deinit(wpa_s->ctrl_iface);
 	wpa_s->ctrl_iface = NULL;
-	}
 	wpa_config_free(wpa_s->conf);
 }
 

wpa_supplicant/wpa_supplicant.c

@@ -1158,8 +1158,8 @@ int wpa_supplicant_reload_configuration(struct wpa_supplicant *wpa_s)
 		    os_strcmp(conf->ctrl_interface,
 			      wpa_s->conf->ctrl_interface) != 0);
 
-	if (reconf_ctrl && wpa_s->ctrl_iface) {
+	if (reconf_ctrl) {
-		wpa_supplicant_ctrl_iface_deinit(wpa_s->ctrl_iface);
+		wpa_supplicant_ctrl_iface_deinit(wpa_s, wpa_s->ctrl_iface);
 		wpa_s->ctrl_iface = NULL;
 	}
 
@@ -6748,10 +6748,8 @@ static void wpa_supplicant_deinit_iface(struct wpa_supplicant *wpa_s,
 	if (terminate)
 		wpa_msg(wpa_s, MSG_INFO, WPA_EVENT_TERMINATING);
 
-	if (wpa_s->ctrl_iface) {
+	wpa_supplicant_ctrl_iface_deinit(wpa_s, wpa_s->ctrl_iface);
-		wpa_supplicant_ctrl_iface_deinit(wpa_s->ctrl_iface);
 	wpa_s->ctrl_iface = NULL;
-	}
 
 #ifdef CONFIG_MESH
 	if (wpa_s->ifmsh) {