net: rtlwifi: properly check for alloc_workqueue() failure

If alloc_workqueue() fails, properly catch this and propagate the error
to the calling functions, so that the devuce initialization will
properly error out.

Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: Bryan Brattlof <hello@bryanbrattlof.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20210503115736.2104747-14-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/net/wireless/realtek/rtlwifi/base.c

@@ -440,9 +440,14 @@ static void rtl_watchdog_wq_callback(struct work_struct *work);
 static void rtl_fwevt_wq_callback(struct work_struct *work);
 static void rtl_c2hcmd_wq_callback(struct work_struct *work);
 
-static void _rtl_init_deferred_work(struct ieee80211_hw *hw)
+static int _rtl_init_deferred_work(struct ieee80211_hw *hw)
 {
 	struct rtl_priv *rtlpriv = rtl_priv(hw);
+	struct workqueue_struct *wq;
+
+	wq = alloc_workqueue("%s", 0, 0, rtlpriv->cfg->name);
+	if (!wq)
+		return -ENOMEM;
 
 	/* <1> timer */
 	timer_setup(&rtlpriv->works.watchdog_timer,
@@ -451,7 +456,8 @@ static void _rtl_init_deferred_work(struct ieee80211_hw *hw)
 		    rtl_easy_concurrent_retrytimer_callback, 0);
 	/* <2> work queue */
 	rtlpriv->works.hw = hw;
-	rtlpriv->works.rtl_wq = alloc_workqueue("%s", 0, 0, rtlpriv->cfg->name);
+	rtlpriv->works.rtl_wq = wq;
+
 	INIT_DELAYED_WORK(&rtlpriv->works.watchdog_wq,
 			  rtl_watchdog_wq_callback);
 	INIT_DELAYED_WORK(&rtlpriv->works.ips_nic_off_wq,
@@ -461,6 +467,7 @@ static void _rtl_init_deferred_work(struct ieee80211_hw *hw)
 			  rtl_swlps_rfon_wq_callback);
 	INIT_DELAYED_WORK(&rtlpriv->works.fwevt_wq, rtl_fwevt_wq_callback);
 	INIT_DELAYED_WORK(&rtlpriv->works.c2hcmd_wq, rtl_c2hcmd_wq_callback);
+	return 0;
 }
 
 void rtl_deinit_deferred_work(struct ieee80211_hw *hw, bool ips_wq)
@@ -559,9 +566,7 @@ int rtl_init_core(struct ieee80211_hw *hw)
 	rtlmac->link_state = MAC80211_NOLINK;
 
 	/* <6> init deferred work */
-	_rtl_init_deferred_work(hw);
-
-	return 0;
+	return _rtl_init_deferred_work(hw);
 }
 EXPORT_SYMBOL_GPL(rtl_init_core);