From patchwork Tue Feb 15 16:11:11 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Kosina X-Patchwork-Id: 12747283 X-Patchwork-Delegate: kvalo@adurom.com 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 943F6C433EF for ; Tue, 15 Feb 2022 16:11:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241424AbiBOQLq (ORCPT ); Tue, 15 Feb 2022 11:11:46 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:42048 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241623AbiBOQL2 (ORCPT ); Tue, 15 Feb 2022 11:11:28 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F2D6C9AD96; Tue, 15 Feb 2022 08:11:17 -0800 (PST) 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 ams.source.kernel.org (Postfix) with ESMTPS id 18207B81B3D; Tue, 15 Feb 2022 16:11:16 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B1570C340F0; Tue, 15 Feb 2022 16:11:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1644941474; bh=i5obIJ0DwCv/AaBdy0yjZuQs07k8fQqBuIkOGBE3DVA=; h=Date:From:To:cc:Subject:In-Reply-To:References:From; b=I175An+sZ3Inl+RRsYN8U/CYYst114L6OrhxbcoSFmG06RAZh3Pw3c0590AKVpLUG 9FRaO1232fmttrW8JAnBnTm95boSVwCgY0ivuExL2nqd84GCgawIcq3U8xI0F2/4j2 z3su7G+u5EUirn/1mf2CWVZHmryEILU6jR8GOGtWVDpCxtplfgkI+p7pYLIVMhiZWb ZLAbh7dR63vkp+q8EgQ0GmpsEr6bYsa02rp7lOEGObAJ5kP2B3za2WAdzWID3mCFkg V7RnrMPpF3rPdvbO6OWOAO0C+8ifpWcoB9Vsjn1xlCmADOy4p9b3rze87XKT3SKHHb 7BbN4m2XwiDVQ== Date: Tue, 15 Feb 2022 17:11:11 +0100 (CET) From: Jiri Kosina To: Johannes Berg cc: linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org, Ping-Ke Shih Subject: [PATCH] rtw89: fix RCU usage in rtw89_core_txq_push() (was Re: [PATCH] mac80211: fix RCU usage in ieee80211_tx_h_select_key()) In-Reply-To: Message-ID: References: User-Agent: Alpine 2.21 (LSU 202 2017-01-01) MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org On Tue, 15 Feb 2022, Johannes Berg wrote: > > > > ieee80211_tx_h_select_key() is performing a series of RCU dereferences, > > but none of the callers seems to be taking RCU read-side lock; let's > > acquire the lock in ieee80211_tx_h_select_key() itself. > > > but but ... > > > ieee80211_tx_dequeue+0x1a7/0x1260 [mac80211 911c23e2351c0ae60b597a67b1204a5ea955e365] > > rtw89_core_txq_work+0x1a6/0x420 [rtw89_core b39ba493f2e517ad75e0f8187ecc24edf58bbbea] > > /** > * ieee80211_tx_dequeue - dequeue a packet from a software tx queue > * > * @hw: pointer as obtained from ieee80211_alloc_hw() > * @txq: pointer obtained from station or virtual interface, or from > * ieee80211_next_txq() > * > * Returns the skb if successful, %NULL if no frame was available. > * > * Note that this must be called in an rcu_read_lock() critical section, > * which can only be released after the SKB was handled. Some pointers in > [...] > > -> driver bug? Right you are, thanks. CCing Ping-Ke Shih; find updated fix below. From: Jiri Kosina Subject: [PATCH] rtw89: fix RCU usage in rtw89_core_txq_push() ieee80211_tx_h_select_key() is performing a series of RCU dereferences, but rtw89_core_txq_push() is calling it (via ieee80211_tx_dequeue_ni()) without RCU read-side lock held; fix that. This addresses the splat below. ============================= WARNING: suspicious RCU usage 5.17.0-rc4-00003-gccad664b7f14 #3 Tainted: G E ----------------------------- net/mac80211/tx.c:593 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 2 locks held by kworker/u33:0/184: #0: ffff9c0b14811d38 ((wq_completion)rtw89_tx_wq){+.+.}-{0:0}, at: process_one_work+0x258/0x660 #1: ffffb97380cf3e78 ((work_completion)(&rtwdev->txq_work)){+.+.}-{0:0}, at: process_one_work+0x258/0x660 stack backtrace: CPU: 8 PID: 184 Comm: kworker/u33:0 Tainted: G E 5.17.0-rc4-00003-gccad664b7f14 #3 473b49ab0e7c2d6af2900c756bfd04efd7a9de13 Hardware name: LENOVO 20UJS2B905/20UJS2B905, BIOS R1CET63W(1.32 ) 04/09/2021 Workqueue: rtw89_tx_wq rtw89_core_txq_work [rtw89_core] Call Trace: dump_stack_lvl+0x58/0x71 ieee80211_tx_h_select_key+0x2c0/0x530 [mac80211 911c23e2351c0ae60b597a67b1204a5ea955e365] ieee80211_tx_dequeue+0x1a7/0x1260 [mac80211 911c23e2351c0ae60b597a67b1204a5ea955e365] rtw89_core_txq_work+0x1a6/0x420 [rtw89_core b39ba493f2e517ad75e0f8187ecc24edf58bbbea] process_one_work+0x2d8/0x660 worker_thread+0x39/0x3e0 ? process_one_work+0x660/0x660 kthread+0xe5/0x110 ? kthread_complete_and_exit+0x20/0x20 ret_from_fork+0x22/0x30 ============================= WARNING: suspicious RCU usage 5.17.0-rc4-00003-gccad664b7f14 #3 Tainted: G E ----------------------------- net/mac80211/tx.c:607 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 2 locks held by kworker/u33:0/184: #0: ffff9c0b14811d38 ((wq_completion)rtw89_tx_wq){+.+.}-{0:0}, at: process_one_work+0x258/0x660 #1: ffffb97380cf3e78 ((work_completion)(&rtwdev->txq_work)){+.+.}-{0:0}, at: process_one_work+0x258/0x660 stack backtrace: CPU: 8 PID: 184 Comm: kworker/u33:0 Tainted: G E 5.17.0-rc4-00003-gccad664b7f14 #3 473b49ab0e7c2d6af2900c756bfd04efd7a9de13 Hardware name: LENOVO 20UJS2B905/20UJS2B905, BIOS R1CET63W(1.32 ) 04/09/2021 Workqueue: rtw89_tx_wq rtw89_core_txq_work [rtw89_core] Call Trace: dump_stack_lvl+0x58/0x71 ieee80211_tx_h_select_key+0x464/0x530 [mac80211 911c23e2351c0ae60b597a67b1204a5ea955e365] ieee80211_tx_dequeue+0x1a7/0x1260 [mac80211 911c23e2351c0ae60b597a67b1204a5ea955e365] rtw89_core_txq_work+0x1a6/0x420 [rtw89_core b39ba493f2e517ad75e0f8187ecc24edf58bbbea] process_one_work+0x2d8/0x660 worker_thread+0x39/0x3e0 ? process_one_work+0x660/0x660 kthread+0xe5/0x110 ? kthread_complete_and_exit+0x20/0x20 ret_from_fork+0x22/0x30 Signed-off-by: Jiri Kosina --- drivers/net/wireless/realtek/rtw89/core.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/realtek/rtw89/core.c b/drivers/net/wireless/realtek/rtw89/core.c index a0737eea9f81..9632e7f218dd 100644 --- a/drivers/net/wireless/realtek/rtw89/core.c +++ b/drivers/net/wireless/realtek/rtw89/core.c @@ -1509,11 +1509,12 @@ static void rtw89_core_txq_push(struct rtw89_dev *rtwdev, unsigned long i; int ret; + rcu_read_lock(); for (i = 0; i < frame_cnt; i++) { skb = ieee80211_tx_dequeue_ni(rtwdev->hw, txq); if (!skb) { rtw89_debug(rtwdev, RTW89_DBG_TXRX, "dequeue a NULL skb\n"); - return; + goto out; } rtw89_core_txq_check_agg(rtwdev, rtwtxq, skb); ret = rtw89_core_tx_write(rtwdev, vif, sta, skb, NULL); @@ -1523,6 +1524,8 @@ static void rtw89_core_txq_push(struct rtw89_dev *rtwdev, break; } } +out: + rcu_read_unlock(); } static u32 rtw89_check_and_reclaim_tx_resource(struct rtw89_dev *rtwdev, u8 tid)