From patchwork Thu Feb 16 19:23:01 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fedor Pchelkin X-Patchwork-Id: 654412 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 4C512C61DA4 for ; Thu, 16 Feb 2023 19:23:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229719AbjBPTXP (ORCPT ); Thu, 16 Feb 2023 14:23:15 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40798 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229492AbjBPTXO (ORCPT ); Thu, 16 Feb 2023 14:23:14 -0500 Received: from mail.ispras.ru (mail.ispras.ru [83.149.199.84]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E009147411; Thu, 16 Feb 2023 11:23:13 -0800 (PST) Received: from fpc.. (unknown [46.242.14.200]) by mail.ispras.ru (Postfix) with ESMTPSA id 0AB5941C612E; Thu, 16 Feb 2023 19:23:12 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 mail.ispras.ru 0AB5941C612E DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ispras.ru; s=default; t=1676575392; bh=fZZ2iOgIhJ3ucWh4NWw0K/zocy8Eivp28hABNY/JFHA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NkGLrrQoVCLyMpuxUXO+dUSu4yqDhS9zYhUT+BXF1uhKTe0gRsoB2WrjDywY3Q68P STxma9qDiGSuVP4k/2uiHvmMJEApdh0wUhyHyrqvzJzKnpJwXAEf9cPxjuEzR0EQ91 r/E8FTqilUY8g7g7XjN3SAXVXqBlpwpCs+x7zBfI= 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 v2] wifi: ath9k: hif_usb: fix memory leak of remain_skbs Date: Thu, 16 Feb 2023 22:23:01 +0300 Message-Id: <20230216192301.171225-1-pchelkin@ispras.ru> X-Mailer: git-send-email 2.34.1 In-Reply-To: <87ttzlqyd4.fsf@toke.dk> References: 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 urbs are deallocated between those two calls due to the device deinitialization or suspend, 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. remain_skb makes sense when receiving two consecutive urbs which are logically linked together, i.e. a specific data field from the first skb indicates a cached skb to be allocated, memcpy'd with some data and subsequently processed in the next call to ath9k_hif_usb_rx_stream(). Urbs deallocation supposedly makes that link irrelevant so we need to free the cached skb in those cases. Fix the leak by introducing a function to explicitly free remain_skb (if it is not NULL) when the rx urbs have been deallocated. remain_skb is NULL when it has not been allocated at all (hif_dev struct is kzalloced) or when it has been processed in next call to ath9k_hif_usb_rx_stream(). 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 --- v1->v2: move ath9k_hif_usb_free_rx_remain_skb call into urbs dealloc function as advised by Toke; add a stat macro drivers/net/wireless/ath/ath9k/hif_usb.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/drivers/net/wireless/ath/ath9k/hif_usb.c b/drivers/net/wireless/ath/ath9k/hif_usb.c index f521dfa2f194..e0130beb304d 100644 --- a/drivers/net/wireless/ath/ath9k/hif_usb.c +++ b/drivers/net/wireless/ath/ath9k/hif_usb.c @@ -534,6 +534,24 @@ 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; + RX_STAT_INC(hif_dev, skb_dropped); + } + 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) { @@ -868,6 +886,7 @@ static int ath9k_hif_usb_alloc_tx_urbs(struct hif_device_usb *hif_dev) static void ath9k_hif_usb_dealloc_rx_urbs(struct hif_device_usb *hif_dev) { usb_kill_anchored_urbs(&hif_dev->rx_submitted); + ath9k_hif_usb_free_rx_remain_skb(hif_dev); } static int ath9k_hif_usb_alloc_rx_urbs(struct hif_device_usb *hif_dev)