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 43698C4332F for ; Wed, 16 Nov 2022 22:36:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234394AbiKPWgZ (ORCPT ); Wed, 16 Nov 2022 17:36:25 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54380 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231688AbiKPWgV (ORCPT ); Wed, 16 Nov 2022 17:36:21 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 503726AEF4; Wed, 16 Nov 2022 14:36:21 -0800 (PST) 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 dfw.source.kernel.org (Postfix) with ESMTPS id DD0A161FF9; Wed, 16 Nov 2022 22:36:20 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3C82DC433C1; Wed, 16 Nov 2022 22:36:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1668638180; bh=PBtBrhR6SnvnYI1/YyRvPYjE5wE5qScBBW+6ZtsQn3A=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=gcmbe9TPSgnloH0Xj5T7JSM1en4RAl/sPLhlLslHSATsbmeAYqb7kUZ5COZ3yBcyq wnqbnvb9+DowAyBAzrLISSZPg2tPtduQFLddITss5ufGKMYuAShI1AQet08WoNyAD5 h/1MbJJHigEQoP19MBKvCQ2u0r1TINkJTvpIwq8fdV+wBKj2VGOXQH/mcN2Ajftm9a sMP7pA2fLjSo7sA8yfZmjbM/lwC868Sh+L7juM1LPT4B9NcF+YE3m2C7p9vzuA4ir4 7nV3KLoZa9hk+0Sfz/1PpShtIMSuLNRuw8F8j7J5uWIw6onHqoD8sU0+D7DS0nAMnH YqISmJDCbmW4w== Date: Wed, 16 Nov 2022 14:36:19 -0800 From: Saeed Mahameed To: Zhang Changzhong Cc: Francois Romieu , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Moritz Fischer , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH net] net: nixge: fix potential memory leak in nixge_start_xmit() Message-ID: References: <1668416136-33530-1-git-send-email-zhangchangzhong@huawei.com> <21641ba0-3ce1-c409-b513-1bbbaeccaa51@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: <21641ba0-3ce1-c409-b513-1bbbaeccaa51@huawei.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 15 Nov 21:20, Zhang Changzhong wrote: >On 2022/11/14 18:40, Francois Romieu wrote: >> Zhang Changzhong : >>> The nixge_start_xmit() returns NETDEV_TX_OK but does not free skb on two >>> error handling cases, which can lead to memory leak. >>> >>> To fix this, return NETDEV_TX_BUSY in case of nixge_check_tx_bd_space() >>> fails and add dev_kfree_skb_any() in case of dma_map_single() fails. >> >> This patch merge two unrelated changes. Please split. >> >>> Fixes: 492caffa8a1a ("net: ethernet: nixge: Add support for National Instruments XGE netdev") >>> Signed-off-by: Zhang Changzhong >>> --- >>> drivers/net/ethernet/ni/nixge.c | 6 ++++-- >>> 1 file changed, 4 insertions(+), 2 deletions(-) >>> >>> diff --git a/drivers/net/ethernet/ni/nixge.c b/drivers/net/ethernet/ni/nixge.c >>> index 19d043b593cc..b9091f9bbc77 100644 >>> --- a/drivers/net/ethernet/ni/nixge.c >>> +++ b/drivers/net/ethernet/ni/nixge.c >>> @@ -521,13 +521,15 @@ static netdev_tx_t nixge_start_xmit(struct sk_buff *skb, >>> if (nixge_check_tx_bd_space(priv, num_frag)) { >>> if (!netif_queue_stopped(ndev)) >>> netif_stop_queue(ndev); >>> - return NETDEV_TX_OK; >>> + return NETDEV_TX_BUSY; >>> } >> >> The driver should probably check the available room before returning >> from hard_start_xmit and turn the check above unlikely(). >> >> Btw there is no lock and the Tx completion is irq driven: the driver >> is racy. :o( >> > >Hi Francois, > >Thanks for you review. I'll make v2 according to your suggestion. > you will probably need to check out: Transmit path guidelines: https://www.kernel.org/doc/Documentation/networking/driver.rst