From patchwork Tue Sep 21 13:06:23 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tetsuo Handa X-Patchwork-Id: 12507799 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 X-Spam-Level: X-Spam-Status: No, score=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 19CADC4332F for ; Tue, 21 Sep 2021 13:06:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F2239610A1 for ; Tue, 21 Sep 2021 13:06:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232897AbhIUNIJ (ORCPT ); Tue, 21 Sep 2021 09:08:09 -0400 Received: from www262.sakura.ne.jp ([202.181.97.72]:64959 "EHLO www262.sakura.ne.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232344AbhIUNIH (ORCPT ); Tue, 21 Sep 2021 09:08:07 -0400 Received: from fsav415.sakura.ne.jp (fsav415.sakura.ne.jp [133.242.250.114]) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTP id 18LD6Rk8084339; Tue, 21 Sep 2021 22:06:27 +0900 (JST) (envelope-from penguin-kernel@i-love.sakura.ne.jp) Received: from www262.sakura.ne.jp (202.181.97.72) by fsav415.sakura.ne.jp (F-Secure/fsigk_smtp/550/fsav415.sakura.ne.jp); Tue, 21 Sep 2021 22:06:27 +0900 (JST) X-Virus-Status: clean(F-Secure/fsigk_smtp/550/fsav415.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 18LD6Qoo084332 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NO); Tue, 21 Sep 2021 22:06:27 +0900 (JST) (envelope-from penguin-kernel@i-love.sakura.ne.jp) To: Kalle Valo , "David S. Miller" , Jakub Kicinski Cc: ath9k-devel@qca.qualcomm.com, linux-wireless@vger.kernel.org, Network Development From: Tetsuo Handa Subject: [PATCH 1/2 (RESEND)] ath9k_htc: fix NULL pointer dereference at ath9k_htc_rxep() Message-ID: <2b88f416-b2cb-7a18-d688-951e6dc3fe92@i-love.sakura.ne.jp> Date: Tue, 21 Sep 2021 22:06:23 +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 lockdep warning followed by kernel panic at ath9k_htc_rxep() [1], for ath9k_htc_rxep() depends on ath9k_rx_init() being already completed. Since ath9k_htc_rxep() is set by ath9k_htc_connect_svc(WMI_BEACON_SVC) from ath9k_init_htc_services(), it is possible that ath9k_htc_rxep() is called via timer interrupt before ath9k_rx_init() from ath9k_init_device() is called. Since we can't call ath9k_init_device() before ath9k_init_htc_services(), let's hold ath9k_htc_rxep() no-op until ath9k_rx_init() completes. Link: https://syzkaller.appspot.com/bug?extid=4d2d56175b934b9a7bf9 [1] Reported-by: syzbot Signed-off-by: Tetsuo Handa Tested-by: syzbot --- drivers/net/wireless/ath/ath9k/htc.h | 1 + drivers/net/wireless/ath/ath9k/htc_drv_txrx.c | 6 ++++++ 2 files changed, 7 insertions(+) diff --git a/drivers/net/wireless/ath/ath9k/htc.h b/drivers/net/wireless/ath/ath9k/htc.h index 0a1634238e67..4f71e962279a 100644 --- a/drivers/net/wireless/ath/ath9k/htc.h +++ b/drivers/net/wireless/ath/ath9k/htc.h @@ -281,6 +281,7 @@ struct ath9k_htc_rxbuf { struct ath9k_htc_rx { struct list_head rxbuf; spinlock_t rxbuflock; + bool initialized; }; #define ATH9K_HTC_TX_CLEANUP_INTERVAL 50 /* ms */ diff --git a/drivers/net/wireless/ath/ath9k/htc_drv_txrx.c b/drivers/net/wireless/ath/ath9k/htc_drv_txrx.c index 8e69e8989f6d..0d4595ee51ba 100644 --- a/drivers/net/wireless/ath/ath9k/htc_drv_txrx.c +++ b/drivers/net/wireless/ath/ath9k/htc_drv_txrx.c @@ -1130,6 +1130,9 @@ void ath9k_htc_rxep(void *drv_priv, struct sk_buff *skb, struct ath9k_htc_rxbuf *rxbuf = NULL, *tmp_buf = NULL; unsigned long flags; + /* Check if ath9k_rx_init() completed. */ + if (!data_race(priv->rx.initialized)) + goto err; spin_lock_irqsave(&priv->rx.rxbuflock, flags); list_for_each_entry(tmp_buf, &priv->rx.rxbuf, list) { if (!tmp_buf->in_process) { @@ -1185,6 +1188,9 @@ int ath9k_rx_init(struct ath9k_htc_priv *priv) list_add_tail(&rxbuf->list, &priv->rx.rxbuf); } + /* Allow ath9k_htc_rxep() to operate. */ + smp_wmb(); + priv->rx.initialized = true; return 0; err: