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=-17.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 BF631C4338F for ; Fri, 6 Aug 2021 07:50:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A45A561050 for ; Fri, 6 Aug 2021 07:50:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243307AbhHFHut (ORCPT ); Fri, 6 Aug 2021 03:50:49 -0400 Received: from relay.sw.ru ([185.231.240.75]:36382 "EHLO relay.sw.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243303AbhHFHun (ORCPT ); Fri, 6 Aug 2021 03:50:43 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=virtuozzo.com; s=relay; h=Content-Type:MIME-Version:Date:Message-ID:Subject :From; bh=OA6nvNuOTkBp2v6M/MwmgL8Zt0WvZey0HynRSPLWDic=; b=Bl2S4YTeIGSm68wVebU 9K634xZ46RFIsbgA3I/EBPir4vGLSFqQ6AyA/TVYs64zNNfzzb/n+h8rpB+XiK0TpqZfHBUtQKu2n MMLehn0V8Von7HsFt3IoydX3MMpDGoUAegFqkccT8D8algsgsB/G0X9A+gkuCirlpRHgP96xlss=; Received: from [10.93.0.56] by relay.sw.ru with esmtp (Exim 4.94.2) (envelope-from ) id 1mBucb-006agE-1u; Fri, 06 Aug 2021 10:50:25 +0300 From: Vasily Averin Subject: [PATCH NET v4 5/7] vrf: use skb_expand_head in vrf_finish_output To: "David S. Miller" , Hideaki YOSHIFUJI , David Ahern , Jakub Kicinski , Eric Dumazet Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, kernel@openvz.org, Julian Wiedmann References: Message-ID: <7429ac6a-aac5-fd56-a109-55110cdf5b64@virtuozzo.com> Date: Fri, 6 Aug 2021 10:50:24 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Unlike skb_realloc_headroom, new helper skb_expand_head does not allocate a new skb if possible. Signed-off-by: Vasily Averin --- v4: fixes null pointer dereference reported by Julian Wiedmann, replace skb->dev by dev = skb_dst(skb)->dev vrf_finish_output() is only called from vrf_output(), it set skb->dev to skb_dst(skb)->dev and calls POSTROUTING netfilter hooks, where output device should not be changed. --- drivers/net/vrf.c | 23 ++++++++--------------- 1 file changed, 8 insertions(+), 15 deletions(-) diff --git a/drivers/net/vrf.c b/drivers/net/vrf.c index 2b1b944..168d4ef 100644 --- a/drivers/net/vrf.c +++ b/drivers/net/vrf.c @@ -857,30 +857,24 @@ static int vrf_finish_output(struct net *net, struct sock *sk, struct sk_buff *s unsigned int hh_len = LL_RESERVED_SPACE(dev); struct neighbour *neigh; bool is_v6gw = false; - int ret = -EINVAL; nf_reset_ct(skb); /* Be paranoid, rather than too clever. */ if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) { - struct sk_buff *skb2; - - skb2 = skb_realloc_headroom(skb, LL_RESERVED_SPACE(dev)); - if (!skb2) { - ret = -ENOMEM; - goto err; + skb = skb_expand_head(skb, hh_len); + if (!skb) { + dev->stats.tx_errors++; + return -ENOMEM; } - if (skb->sk) - skb_set_owner_w(skb2, skb->sk); - - consume_skb(skb); - skb = skb2; } rcu_read_lock_bh(); neigh = ip_neigh_for_gw(rt, skb, &is_v6gw); if (!IS_ERR(neigh)) { + int ret; + sock_confirm_neigh(skb, neigh); /* if crossing protocols, can not use the cached header */ ret = neigh_output(neigh, skb, is_v6gw); @@ -889,9 +883,8 @@ static int vrf_finish_output(struct net *net, struct sock *sk, struct sk_buff *s } rcu_read_unlock_bh(); -err: - vrf_tx_error(skb->dev, skb); - return ret; + vrf_tx_error(dev, skb); + return -EINVAL; } static int vrf_output(struct net *net, struct sock *sk, struct sk_buff *skb) -- 1.8.3.1