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 F07DBC433F5 for ; Mon, 24 Jan 2022 21:39:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1456464AbiAXVjN (ORCPT ); Mon, 24 Jan 2022 16:39:13 -0500 Received: from ams.source.kernel.org ([145.40.68.75]:41100 "EHLO ams.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1359700AbiAXV07 (ORCPT ); Mon, 24 Jan 2022 16:26:59 -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 7F024B811A2; Mon, 24 Jan 2022 21:26:57 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B74DFC340E4; Mon, 24 Jan 2022 21:26:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1643059616; bh=0NPR2GEkXmlKshR2DCdw5F1yXLjr3XEZ5JAnE8LMcEk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YlN9bp9oMRbjuGrcQktLgo20UfiOkYFRw0fqE8ITFyF+EaG4/8W2xIu7s5H4LdtKm mPCW/6NP1pmzF5fmoOOt0dtuuFR+Qm2sVZKUFsZpaAelv9InkIH2rxfpZPyRy9El+m aimCXK+ZweAMvKqnGkgEYYIfRiqhBymCLtX2IkUw= 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 5.16 0675/1039] ath9k_htc: fix NULL pointer dereference at ath9k_htc_rxep() Date: Mon, 24 Jan 2022 19:41:04 +0100 Message-Id: <20220124184148.057636054@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220124184125.121143506@linuxfoundation.org> References: <20220124184125.121143506@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: Tetsuo Handa [ Upstream commit b0ec7e55fce65f125bd1d7f02e2dc4de62abee34 ] 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 Signed-off-by: Kalle Valo Link: https://lore.kernel.org/r/2b88f416-b2cb-7a18-d688-951e6dc3fe92@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 | 8 ++++++++ 2 files changed, 9 insertions(+) diff --git a/drivers/net/wireless/ath/ath9k/htc.h b/drivers/net/wireless/ath/ath9k/htc.h index 0a1634238e673..4f71e962279af 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 8e69e8989f6d3..e7a21eaf3a68d 100644 --- a/drivers/net/wireless/ath/ath9k/htc_drv_txrx.c +++ b/drivers/net/wireless/ath/ath9k/htc_drv_txrx.c @@ -1130,6 +1130,10 @@ 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 +1189,10 @@ 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: -- 2.34.1