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 X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BE581C432C0 for ; Tue, 3 Dec 2019 03:08:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9CEF12068E for ; Tue, 3 Dec 2019 03:08:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726738AbfLCDIq (ORCPT ); Mon, 2 Dec 2019 22:08:46 -0500 Received: from szxga04-in.huawei.com ([45.249.212.190]:7190 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726254AbfLCDIp (ORCPT ); Mon, 2 Dec 2019 22:08:45 -0500 Received: from DGGEMS410-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id 84BE163590DDBFB96CCA; Tue, 3 Dec 2019 11:08:43 +0800 (CST) Received: from localhost.localdomain (10.69.192.56) by DGGEMS410-HUB.china.huawei.com (10.3.19.210) with Microsoft SMTP Server id 14.3.439.0; Tue, 3 Dec 2019 11:08:34 +0800 From: Huazhong Tan To: CC: , , , , , , Yunsheng Lin , Huazhong Tan Subject: [PATCH net 2/3] net: hns3: fix a use after free problem in hns3_nic_maybe_stop_tx() Date: Tue, 3 Dec 2019 11:08:54 +0800 Message-ID: <1575342535-2981-3-git-send-email-tanhuazhong@huawei.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1575342535-2981-1-git-send-email-tanhuazhong@huawei.com> References: <1575342535-2981-1-git-send-email-tanhuazhong@huawei.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.69.192.56] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Yunsheng Lin Currently, hns3_nic_maybe_stop_tx() uses skb_copy() to linearize a SKB if the BD num required by the SKB does not meet the hardware limitation, and it linearizes the SKB by allocating a new SKB and freeing the old SKB, if hns3_nic_maybe_stop_tx() returns -EBUSY, the sch_direct_xmit() still hold reference to old SKB and try to retransmit the old SKB when dev_hard_start_xmit() return TX_BUSY, which may cause use after freed problem. This patch fixes it by using __skb_linearize() to linearize the SKB in hns3_nic_maybe_stop_tx(). Fixes: 51e8439f3496 ("net: hns3: add 8 BD limit for tx flow") Signed-off-by: Yunsheng Lin Signed-off-by: Huazhong Tan --- drivers/net/ethernet/hisilicon/hns3/hns3_enet.c | 19 ++++++------------- 1 file changed, 6 insertions(+), 13 deletions(-) diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c index b2bb8e2..cbdb688 100644 --- a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c +++ b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c @@ -1287,33 +1287,26 @@ static bool hns3_skb_need_linearized(struct sk_buff *skb, unsigned int *bd_size, } static int hns3_nic_maybe_stop_tx(struct net_device *netdev, - struct sk_buff **out_skb) + struct sk_buff *skb) { struct hns3_nic_priv *priv = netdev_priv(netdev); unsigned int bd_size[HNS3_MAX_TSO_BD_NUM + 1U]; - struct sk_buff *skb = *out_skb; struct hns3_enet_ring *ring; unsigned int bd_num; ring = &priv->ring[skb->queue_mapping]; bd_num = hns3_tx_bd_num(skb, bd_size); if (unlikely(bd_num > HNS3_MAX_NON_TSO_BD_NUM)) { - struct sk_buff *new_skb; if (bd_num <= HNS3_MAX_TSO_BD_NUM && skb_is_gso(skb) && !hns3_skb_need_linearized(skb, bd_size, bd_num)) goto out; - /* manual split the send packet */ - new_skb = skb_copy(skb, GFP_ATOMIC); - if (!new_skb) + if (__skb_linearize(skb)) return -ENOMEM; - dev_kfree_skb_any(skb); - *out_skb = new_skb; - - bd_num = hns3_tx_bd_count(new_skb->len); - if ((skb_is_gso(new_skb) && bd_num > HNS3_MAX_TSO_BD_NUM) || - (!skb_is_gso(new_skb) && + bd_num = hns3_tx_bd_count(skb->len); + if ((skb_is_gso(skb) && bd_num > HNS3_MAX_TSO_BD_NUM) || + (!skb_is_gso(skb) && bd_num > HNS3_MAX_NON_TSO_BD_NUM)) return -ENOMEM; @@ -1416,7 +1409,7 @@ netdev_tx_t hns3_nic_net_xmit(struct sk_buff *skb, struct net_device *netdev) /* Prefetch the data used later */ prefetch(skb->data); - ret = hns3_nic_maybe_stop_tx(netdev, &skb); + ret = hns3_nic_maybe_stop_tx(netdev, skb); if (unlikely(ret <= 0)) { if (ret == -EBUSY) { u64_stats_update_begin(&ring->syncp); -- 2.7.4