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 209E5C4332F for ; Tue, 15 Nov 2022 23:03:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231761AbiKOXDg (ORCPT ); Tue, 15 Nov 2022 18:03:36 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53426 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230224AbiKOXDd (ORCPT ); Tue, 15 Nov 2022 18:03:33 -0500 Received: from violet.fr.zoreil.com (violet.fr.zoreil.com [IPv6:2001:4b98:dc0:41:216:3eff:fe56:8398]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4E0901A218; Tue, 15 Nov 2022 15:03:32 -0800 (PST) Received: from violet.fr.zoreil.com ([127.0.0.1]) by violet.fr.zoreil.com (8.17.1/8.17.1) with ESMTP id 2AFN3A5S879452; Wed, 16 Nov 2022 00:03:10 +0100 DKIM-Filter: OpenDKIM Filter v2.11.0 violet.fr.zoreil.com 2AFN3A5S879452 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fr.zoreil.com; s=v20220413; t=1668553390; bh=IlM07V2nk3Vlr1tkiatmuPGZypdU+mfnuL4S/5X5luE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=CiWouXgUFhV5lv0v9bDtJhwRnsiJgxdF4ySqrNv6J7ayGCBOezJsDMummzmGK1Wez opHkPBg+qH+A6TDe6JbwgxkdnHg8ryFGdl1wjT96y2kbHdXEDlshZxCcguCvpj9q4b vnEbqcoC0qLC9WO7y7nn66KAi6IuupFDBlPc0XLc= Received: (from romieu@localhost) by violet.fr.zoreil.com (8.17.1/8.17.1/Submit) id 2AFN3Afl879451; Wed, 16 Nov 2022 00:03:10 +0100 Date: Wed, 16 Nov 2022 00:03:10 +0100 From: Francois Romieu To: Zhang Changzhong Cc: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, mdf@kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH net v2 2/3] net: nixge: avoid overwriting buffer descriptor Message-ID: References: <1668525024-38409-1-git-send-email-zhangchangzhong@huawei.com> <1668525024-38409-3-git-send-email-zhangchangzhong@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1668525024-38409-3-git-send-email-zhangchangzhong@huawei.com> X-Organisation: Land of Sunshine Inc. Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Zhang Changzhong : > The check on the number of available BDs is incorrect because BDs are > required not only for frags but also for skb. This may result in > overwriting BD that is still in use. > > Fixes: 492caffa8a1a ("net: ethernet: nixge: Add support for National Instruments XGE netdev") > Signed-off-by: Zhang Changzhong > --- > drivers/net/ethernet/ni/nixge.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/net/ethernet/ni/nixge.c b/drivers/net/ethernet/ni/nixge.c > index d8cd520..91b7ebc 100644 > --- a/drivers/net/ethernet/ni/nixge.c > +++ b/drivers/net/ethernet/ni/nixge.c > @@ -518,7 +518,7 @@ static netdev_tx_t nixge_start_xmit(struct sk_buff *skb, > cur_p = &priv->tx_bd_v[priv->tx_bd_tail]; > tx_skb = &priv->tx_skb[priv->tx_bd_tail]; > > - if (nixge_check_tx_bd_space(priv, num_frag)) { > + if (nixge_check_tx_bd_space(priv, num_frag + 1)) { > if (!netif_queue_stopped(ndev)) > netif_stop_queue(ndev); > return NETDEV_TX_OK; > -- Reviewed-by: Francois Romieu It's fine as a minimal fix but something may be done in a future patch to avoid the confusing nixge_check_tx_bd_space(..., num_frag + 1) vs static int nixge_check_tx_bd_space(struct nixge_priv *priv, int num_frag) (use "slots" for the latter ?). Consider waiting for -stable people's opinion before rushing into it as it may make their life harder. -- Ueimor