From patchwork Sun Sep 12 07:18:33 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tetsuo Handa X-Patchwork-Id: 509683 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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_SANE_1 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 61FB3C433F5 for ; Sun, 12 Sep 2021 07:18:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2DD8C610A6 for ; Sun, 12 Sep 2021 07:18:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229783AbhILHT4 (ORCPT ); Sun, 12 Sep 2021 03:19:56 -0400 Received: from www262.sakura.ne.jp ([202.181.97.72]:55923 "EHLO www262.sakura.ne.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229512AbhILHTz (ORCPT ); Sun, 12 Sep 2021 03:19:55 -0400 Received: from fsav411.sakura.ne.jp (fsav411.sakura.ne.jp [133.242.250.110]) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTP id 18C7IZhv008575; Sun, 12 Sep 2021 16:18:35 +0900 (JST) (envelope-from penguin-kernel@i-love.sakura.ne.jp) Received: from www262.sakura.ne.jp (202.181.97.72) by fsav411.sakura.ne.jp (F-Secure/fsigk_smtp/550/fsav411.sakura.ne.jp); Sun, 12 Sep 2021 16:18:35 +0900 (JST) X-Virus-Status: clean(F-Secure/fsigk_smtp/550/fsav411.sakura.ne.jp) Received: from [192.168.1.9] (M106072142033.v4.enabler.ne.jp [106.72.142.33]) (authenticated bits=0) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTPSA id 18C7IZDC008571 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NO); Sun, 12 Sep 2021 16:18:35 +0900 (JST) (envelope-from penguin-kernel@i-love.sakura.ne.jp) To: Kalle Valo , ath9k-devel@qca.qualcomm.com Cc: linux-wireless From: Tetsuo Handa Subject: [PATCH] ath9k_htc: fix NULL pointer dereference at ath9k_htc_tx_get_packet() Message-ID: <7145c55e-6b1d-d8be-57cc-6639e4e5fee2@i-love.sakura.ne.jp> Date: Sun, 12 Sep 2021 16:18:33 +0900 User-Agent: Mozilla/5.0 (Windows NT 6.3; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.14.0 MIME-Version: 1.0 Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org syzbot is reporting NULL pointer dereference at get_htc_epid_queue() from ath9k_htc_tx_get_packet() from ath9k_htc_txstatus() [1], for ath9k_wmi_event_tasklet(WMI_TXSTATUS_EVENTID) depends on spin_lock_init() from ath9k_init_priv() being already completed. Since ath9k_wmi_event_tasklet() is set by ath9k_init_wmi() from ath9k_htc_probe_device(), it is possible that ath9k_wmi_event_tasklet() is called via tasklet interrupt before spin_lock_init() from ath9k_init_priv() from ath9k_init_device() from ath9k_htc_probe_device() is called. Let's hold ath9k_wmi_event_tasklet(WMI_TXSTATUS_EVENTID) no-op until ath9k_tx_init() completes. Link: https://syzkaller.appspot.com/bug?extid=31d54c60c5b254d6f75b [1] Reported-by: syzbot Signed-off-by: Tetsuo Handa Tested-by: syzbot+31d54c60c5b254d6f75b@syzkaller.appspotmail.com --- drivers/net/wireless/ath/ath9k/htc.h | 1 + drivers/net/wireless/ath/ath9k/htc_drv_txrx.c | 3 +++ drivers/net/wireless/ath/ath9k/wmi.c | 3 +++ 3 files changed, 7 insertions(+) diff --git a/drivers/net/wireless/ath/ath9k/htc.h b/drivers/net/wireless/ath/ath9k/htc.h index 4f71e962279a..6b45e63fae4b 100644 --- a/drivers/net/wireless/ath/ath9k/htc.h +++ b/drivers/net/wireless/ath/ath9k/htc.h @@ -306,6 +306,7 @@ struct ath9k_htc_tx { DECLARE_BITMAP(tx_slot, MAX_TX_BUF_NUM); struct timer_list cleanup_timer; spinlock_t tx_lock; + bool initialized; }; struct ath9k_htc_tx_ctl { diff --git a/drivers/net/wireless/ath/ath9k/htc_drv_txrx.c b/drivers/net/wireless/ath/ath9k/htc_drv_txrx.c index 0d4595ee51ba..a5240a7f8c00 100644 --- a/drivers/net/wireless/ath/ath9k/htc_drv_txrx.c +++ b/drivers/net/wireless/ath/ath9k/htc_drv_txrx.c @@ -813,6 +813,9 @@ int ath9k_tx_init(struct ath9k_htc_priv *priv) skb_queue_head_init(&priv->tx.data_vi_queue); skb_queue_head_init(&priv->tx.data_vo_queue); skb_queue_head_init(&priv->tx.tx_failed); + /* Allow ath9k_wmi_event_tasklet(WMI_TXSTATUS_EVENTID) to operate. */ + smp_wmb(); + priv->tx.initialized = true; return 0; } diff --git a/drivers/net/wireless/ath/ath9k/wmi.c b/drivers/net/wireless/ath/ath9k/wmi.c index fe29ad4b9023..7e17d86bf5d3 100644 --- a/drivers/net/wireless/ath/ath9k/wmi.c +++ b/drivers/net/wireless/ath/ath9k/wmi.c @@ -169,6 +169,9 @@ void ath9k_wmi_event_tasklet(struct tasklet_struct *t) &wmi->drv_priv->fatal_work); break; case WMI_TXSTATUS_EVENTID: + /* Check if ath9k_tx_init() completed. */ + if (!data_race(priv->tx.initialized)) + break; spin_lock_bh(&priv->tx.tx_lock); if (priv->tx.flags & ATH9K_HTC_OP_TX_DRAIN) { spin_unlock_bh(&priv->tx.tx_lock);