From patchwork Mon Jan 24 18:41:28 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 535762 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 A507CC41535 for ; Mon, 24 Jan 2022 20:42:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350802AbiAXUlk (ORCPT ); Mon, 24 Jan 2022 15:41:40 -0500 Received: from ams.source.kernel.org ([145.40.68.75]:40890 "EHLO ams.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1388260AbiAXUiZ (ORCPT ); Mon, 24 Jan 2022 15:38:25 -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 ams.source.kernel.org (Postfix) with ESMTPS id 2D1B5B811F9; Mon, 24 Jan 2022 20:38:24 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2F97DC340E5; Mon, 24 Jan 2022 20:38:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1643056702; bh=XOsj6tMeo3byH1VXmZp4CqHcytz5W+S7VP6NCTNikdo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=C0yvE8JueFYNKtq7OmvIpo3QZ2vgtZVfk6dYlKyBkv40amAkIHhZxpIQMl7ntclgj AffTcPTt7k6IES7HfvUWJtaBRGV28ujbRwP3n+ypyb8MaPc+NvD/paJMgHEl36q8P/ b5IZAQyqLbmrX1M2Xb2/90dkvVJvW6uFLzEoUifI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot , Tetsuo Handa , Kalle Valo , Sasha Levin Subject: [PATCH 5.15 571/846] ath9k_htc: fix NULL pointer dereference at ath9k_htc_tx_get_packet() Date: Mon, 24 Jan 2022 19:41:28 +0100 Message-Id: <20220124184120.735990926@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 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Tetsuo Handa [ Upstream commit 8b3046abc99eefe11438090bcc4ec3a3994b55d0 ] syzbot is reporting lockdep warning at ath9k_wmi_event_tasklet() followed by kernel panic 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 Signed-off-by: Kalle Valo Link: https://lore.kernel.org/r/77b76ac8-2bee-6444-d26c-8c30858b8daa@i-love.sakura.ne.jp Signed-off-by: Sasha Levin --- drivers/net/wireless/ath/ath9k/htc.h | 1 + drivers/net/wireless/ath/ath9k/htc_drv_txrx.c | 5 +++++ drivers/net/wireless/ath/ath9k/wmi.c | 4 ++++ 3 files changed, 10 insertions(+) diff --git a/drivers/net/wireless/ath/ath9k/htc.h b/drivers/net/wireless/ath/ath9k/htc.h index 4f71e962279af..6b45e63fae4ba 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 e7a21eaf3a68d..6a850a0bfa8ad 100644 --- a/drivers/net/wireless/ath/ath9k/htc_drv_txrx.c +++ b/drivers/net/wireless/ath/ath9k/htc_drv_txrx.c @@ -813,6 +813,11 @@ 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 fe29ad4b9023c..f315c54bd3ac0 100644 --- a/drivers/net/wireless/ath/ath9k/wmi.c +++ b/drivers/net/wireless/ath/ath9k/wmi.c @@ -169,6 +169,10 @@ 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);