From patchwork Sun Feb 12 14:52:38 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fedor Pchelkin X-Patchwork-Id: 653098 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 7F169C636D3 for ; Sun, 12 Feb 2023 14:53:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229689AbjBLOxF (ORCPT ); Sun, 12 Feb 2023 09:53:05 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52974 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229679AbjBLOxD (ORCPT ); Sun, 12 Feb 2023 09:53:03 -0500 Received: from mail.ispras.ru (mail.ispras.ru [83.149.199.84]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C166F11E8F; Sun, 12 Feb 2023 06:53:01 -0800 (PST) Received: from fpc.. (unknown [46.242.14.200]) by mail.ispras.ru (Postfix) with ESMTPSA id 0730D44C101D; Sun, 12 Feb 2023 14:53:00 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 mail.ispras.ru 0730D44C101D DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ispras.ru; s=default; t=1676213580; bh=UAcNy4s3ciQEP3RErmHWu+rLoVRfErmjChDp+m1b2o4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=O+VjZMC49qlkZexnhD4yW9hADORqhf5tfgncJUuHBa2rcYCSUcuxyScRpertiGcAr tab3kdwH7MrvqCkW3ofbxS/ts5nyUzDpTfwJ/LO9QbxLPWtNflR/jpBIy3GDh40ZKK unEbzBqH8Fs3m7503RjagPPO6Vl+rfx2LFrRFo0E= From: Fedor Pchelkin To: =?utf-8?q?Toke_H=C3=B8iland-J=C3=B8rgensen?= Cc: Fedor Pchelkin , Kalle Valo , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , "John W. Linville" , Vasanthakumar Thiagarajan , Senthil Balasubramanian , Sujith , linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Alexey Khoroshilov , lvc-project@linuxtesting.org Subject: [PATCH 1/1] wifi: ath9k: hif_usb: fix memory leak of remain_skbs Date: Sun, 12 Feb 2023 17:52:38 +0300 Message-Id: <20230212145238.123055-2-pchelkin@ispras.ru> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230212145238.123055-1-pchelkin@ispras.ru> References: <20230212145238.123055-1-pchelkin@ispras.ru> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org hif_dev->remain_skb is allocated and used exclusively in ath9k_hif_usb_rx_stream(). It is implied that an allocated remain_skb is processed and subsequently freed (in error paths) only during the next call of ath9k_hif_usb_rx_stream(). So, if the device is deinitialized between those two calls or if the skb contents are incorrect, it is possible that ath9k_hif_usb_rx_stream() is not called next time and the allocated remain_skb is leaked. Our local Syzkaller instance was able to trigger that. Fix the leak by introducing a function to explicitly free remain_skb (if it is not NULL) when the device is being deinitialized. remain_skb is NULL when it has not been allocated at all (hif_dev struct is kzalloced) or when it has been proccesed in next call to ath9k_hif_usb_rx_stream(). Proper spinlocks are held to prevent possible concurrent access to remain_skb from the interrupt context ath9k_hif_usb_rx_stream(). These accesses should not happen as rx_urbs have been deallocated before but it prevents a dangerous race condition in these cases. Found by Linux Verification Center (linuxtesting.org) with Syzkaller. Fixes: fb9987d0f748 ("ath9k_htc: Support for AR9271 chipset.") Signed-off-by: Fedor Pchelkin Signed-off-by: Alexey Khoroshilov --- drivers/net/wireless/ath/ath9k/hif_usb.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/drivers/net/wireless/ath/ath9k/hif_usb.c b/drivers/net/wireless/ath/ath9k/hif_usb.c index f521dfa2f194..e03ab972edf7 100644 --- a/drivers/net/wireless/ath/ath9k/hif_usb.c +++ b/drivers/net/wireless/ath/ath9k/hif_usb.c @@ -534,6 +534,23 @@ static struct ath9k_htc_hif hif_usb = { .send = hif_usb_send, }; +/* Need to free remain_skb allocated in ath9k_hif_usb_rx_stream + * in case ath9k_hif_usb_rx_stream wasn't called next time to + * process the buffer and subsequently free it. + */ +static void ath9k_hif_usb_free_rx_remain_skb(struct hif_device_usb *hif_dev) +{ + unsigned long flags; + + spin_lock_irqsave(&hif_dev->rx_lock, flags); + if (hif_dev->remain_skb) { + dev_kfree_skb_any(hif_dev->remain_skb); + hif_dev->remain_skb = NULL; + hif_dev->rx_remain_len = 0; + } + spin_unlock_irqrestore(&hif_dev->rx_lock, flags); +} + static void ath9k_hif_usb_rx_stream(struct hif_device_usb *hif_dev, struct sk_buff *skb) { @@ -1129,6 +1146,7 @@ static int ath9k_hif_usb_dev_init(struct hif_device_usb *hif_dev) static void ath9k_hif_usb_dev_deinit(struct hif_device_usb *hif_dev) { ath9k_hif_usb_dealloc_urbs(hif_dev); + ath9k_hif_usb_free_rx_remain_skb(hif_dev); } /*