From patchwork Mon Jun 22 13:21:11 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Reto Schneider X-Patchwork-Id: 215274 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4B225C433E0 for ; Mon, 22 Jun 2020 13:39:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2747320738 for ; Mon, 22 Jun 2020 13:39:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728951AbgFVNjl (ORCPT ); Mon, 22 Jun 2020 09:39:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49330 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728212AbgFVNjl (ORCPT ); Mon, 22 Jun 2020 09:39:41 -0400 Received: from mxout014.mail.hostpoint.ch (mxout014.mail.hostpoint.ch [IPv6:2a00:d70:0:e::314]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D13ADC061573 for ; Mon, 22 Jun 2020 06:39:40 -0700 (PDT) Received: from [10.0.2.46] (helo=asmtp013.mail.hostpoint.ch) by mxout014.mail.hostpoint.ch with esmtp (Exim 4.92.3 (FreeBSD)) (envelope-from ) id 1jnMPP-000Hxu-Ke; Mon, 22 Jun 2020 15:22:47 +0200 Received: from [2a02:168:6182:1:4840:f038:bf12:aa10] (helo=ryzen2700.dss.husqvarnagroup.com) by asmtp013.mail.hostpoint.ch with esmtpsa (TLSv1.3:TLS_AES_256_GCM_SHA384:256) (Exim 4.92.3 (FreeBSD)) (envelope-from ) id 1jnMPP-0006GV-F3; Mon, 22 Jun 2020 15:22:47 +0200 X-Authenticated-Sender-Id: reto-schneider@reto-schneider.ch From: Reto Schneider To: linux-wireless@vger.kernel.org Cc: Larry.Finger@lwfinger.net, Reto Schneider Subject: [PATCH 1/3] rtl8192cu: Fix deadlock Date: Mon, 22 Jun 2020 15:21:11 +0200 Message-Id: <20200622132113.14508-2-code@reto-schneider.ch> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200622132113.14508-1-code@reto-schneider.ch> References: <20200622132113.14508-1-code@reto-schneider.ch> MIME-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org Prevent code from calling itself indirectly, causing the driver to hang and consume 100% CPU. Without this fix, the following script can bring down a single CPU system: ``` while true; do rmmod rtl8192cu modprobe rtl8192cu done ``` Signed-off-by: Reto Schneider --- drivers/net/wireless/realtek/rtlwifi/usb.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/net/wireless/realtek/rtlwifi/usb.c b/drivers/net/wireless/realtek/rtlwifi/usb.c index c66c6dc00378..d3bbfc0171f6 100644 --- a/drivers/net/wireless/realtek/rtlwifi/usb.c +++ b/drivers/net/wireless/realtek/rtlwifi/usb.c @@ -680,8 +680,10 @@ static void _rtl_usb_cleanup_rx(struct ieee80211_hw *hw) tasklet_kill(&rtlusb->rx_work_tasklet); cancel_work_sync(&rtlpriv->works.lps_change_work); - flush_workqueue(rtlpriv->works.rtl_wq); - destroy_workqueue(rtlpriv->works.rtl_wq); + if (rtlpriv->works.rtl_wq) { + destroy_workqueue(rtlpriv->works.rtl_wq); + rtlpriv->works.rtl_wq = NULL; + } skb_queue_purge(&rtlusb->rx_queue);