From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0D9BDC433F5 for ; Mon, 24 Jan 2022 20:32:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1356845AbiAXUcm (ORCPT ); Mon, 24 Jan 2022 15:32:42 -0500 Received: from dfw.source.kernel.org ([139.178.84.217]:46800 "EHLO dfw.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349067AbiAXUWs (ORCPT ); Mon, 24 Jan 2022 15:22:48 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 579CC61502; Mon, 24 Jan 2022 20:22:48 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2F8E8C340E5; Mon, 24 Jan 2022 20:22:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1643055767; bh=RkngHeAeVCkGRFWJ2UEUeqVNrmIJmwasCnUlDu8quqk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fhuRwTXJ/vX6b3dKAjx5k0ucZ/OjqlAfwNJcI2WmPeJ4qZRAnGqBCDmuUmZvoVK3a t0JGgpia5CMAY1EDEvQ2zztQVSbeoAKFqVwqX3PGTVgtTYALDHY2WQAtFugNJZsGAR ndAL4gNLQmyKqkdAOwWdzPX0Q3ObMLCKUzsYHv8U= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Douglas Anderson , TOTE Robot , Brian Norris , Kalle Valo , Sasha Levin Subject: [PATCH 5.15 226/846] mwifiex: Fix possible ABBA deadlock Date: Mon, 24 Jan 2022 19:35:43 +0100 Message-Id: <20220124184108.712569914@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220124184100.867127425@linuxfoundation.org> References: <20220124184100.867127425@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Brian Norris [ Upstream commit 1b8bb8919ef81bfc8873d223b9361f1685f2106d ] Quoting Jia-Ju Bai : mwifiex_dequeue_tx_packet() spin_lock_bh(&priv->wmm.ra_list_spinlock); --> Line 1432 (Lock A) mwifiex_send_addba() spin_lock_bh(&priv->sta_list_spinlock); --> Line 608 (Lock B) mwifiex_process_sta_tx_pause() spin_lock_bh(&priv->sta_list_spinlock); --> Line 398 (Lock B) mwifiex_update_ralist_tx_pause() spin_lock_bh(&priv->wmm.ra_list_spinlock); --> Line 941 (Lock A) Similar report for mwifiex_process_uap_tx_pause(). While the locking expectations in this driver are a bit unclear, the Fixed commit only intended to protect the sta_ptr, so we can drop the lock as soon as we're done with it. IIUC, this deadlock cannot actually happen, because command event processing (which calls mwifiex_process_sta_tx_pause()) is sequentialized with TX packet processing (e.g., mwifiex_dequeue_tx_packet()) via the main loop (mwifiex_main_process()). But it's good not to leave this potential issue lurking. Fixes: f0f7c2275fb9 ("mwifiex: minor cleanups w/ sta_list_spinlock in cfg80211.c") Cc: Douglas Anderson Reported-by: TOTE Robot Link: https://lore.kernel.org/linux-wireless/0e495b14-efbb-e0da-37bd-af6bd677ee2c@gmail.com/ Signed-off-by: Brian Norris Reviewed-by: Douglas Anderson Signed-off-by: Kalle Valo Link: https://lore.kernel.org/r/YaV0pllJ5p/EuUat@google.com Signed-off-by: Sasha Levin --- drivers/net/wireless/marvell/mwifiex/sta_event.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/net/wireless/marvell/mwifiex/sta_event.c b/drivers/net/wireless/marvell/mwifiex/sta_event.c index 68c63268e2e6b..2b2e6e0166e14 100644 --- a/drivers/net/wireless/marvell/mwifiex/sta_event.c +++ b/drivers/net/wireless/marvell/mwifiex/sta_event.c @@ -365,10 +365,12 @@ static void mwifiex_process_uap_tx_pause(struct mwifiex_private *priv, sta_ptr = mwifiex_get_sta_entry(priv, tp->peermac); if (sta_ptr && sta_ptr->tx_pause != tp->tx_pause) { sta_ptr->tx_pause = tp->tx_pause; + spin_unlock_bh(&priv->sta_list_spinlock); mwifiex_update_ralist_tx_pause(priv, tp->peermac, tp->tx_pause); + } else { + spin_unlock_bh(&priv->sta_list_spinlock); } - spin_unlock_bh(&priv->sta_list_spinlock); } } @@ -400,11 +402,13 @@ static void mwifiex_process_sta_tx_pause(struct mwifiex_private *priv, sta_ptr = mwifiex_get_sta_entry(priv, tp->peermac); if (sta_ptr && sta_ptr->tx_pause != tp->tx_pause) { sta_ptr->tx_pause = tp->tx_pause; + spin_unlock_bh(&priv->sta_list_spinlock); mwifiex_update_ralist_tx_pause(priv, tp->peermac, tp->tx_pause); + } else { + spin_unlock_bh(&priv->sta_list_spinlock); } - spin_unlock_bh(&priv->sta_list_spinlock); } } } -- 2.34.1