From patchwork Tue Mar 31 08:57:56 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 228638 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=-6.9 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 5AD38C2D0EE for ; Tue, 31 Mar 2020 09:12:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2828720675 for ; Tue, 31 Mar 2020 09:12:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585645957; bh=WEq957zAfjyZHs7RPLZbxFpac6ucSHDGcB02beUwI1Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=XjMk4K+3H9SbejitHKewezCROuU0PcNlVZ8GzJtLfLZg6IdWVDitlw+xwN9CbUWy4 d4GqRRhdjLW+ePG97iIQuKiLV5FS5xmhNz53llF8sMiv41hbdpdpkMbAPMk1Y6Dfpn ouGIaExrz+FCzNT8RfD1qawfubrqKrEV30lU1h5M= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731556AbgCaJML (ORCPT ); Tue, 31 Mar 2020 05:12:11 -0400 Received: from mail.kernel.org ([198.145.29.99]:58192 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731532AbgCaJMK (ORCPT ); Tue, 31 Mar 2020 05:12:10 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id AFEF320772; Tue, 31 Mar 2020 09:12:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585645930; bh=WEq957zAfjyZHs7RPLZbxFpac6ucSHDGcB02beUwI1Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=We9akCHw6bBN5mrCwKppS28p1+4cqIEmDTqgeeYWOx27KIXK+XqY+OocWxXUxItlW zcntXz/6c4n4y7dz8Cjwngop/Bl56vn1GlClPC5WZFzdLzeTF6+AdODO8AKLmvcU8J kxScNZET6qzNgouJOS2kilwE9QZ8b34ip/L88Z2Q= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Dumazet , Martin Zaharinov , Florian Westphal , Pablo Neira Ayuso , "David S. Miller" Subject: [PATCH 5.4 036/155] tcp: ensure skb->dev is NULL before leaving TCP stack Date: Tue, 31 Mar 2020 10:57:56 +0200 Message-Id: <20200331085422.435199048@linuxfoundation.org> X-Mailer: git-send-email 2.26.0 In-Reply-To: <20200331085418.274292403@linuxfoundation.org> References: <20200331085418.274292403@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Eric Dumazet [ Upstream commit b738a185beaab8728943acdb3e67371b8a88185e ] skb->rbnode is sharing three skb fields : next, prev, dev When a packet is sent, TCP keeps the original skb (master) in a rtx queue, which was converted to rbtree a while back. __tcp_transmit_skb() is responsible to clone the master skb, and add the TCP header to the clone before sending it to network layer. skb_clone() already clears skb->next and skb->prev, but copies the master oskb->dev into the clone. We need to clear skb->dev, otherwise lower layers could interpret the value as a pointer to a netdev. This old bug surfaced recently when commit 28f8bfd1ac94 ("netfilter: Support iif matches in POSTROUTING") was merged. Before this netfilter commit, skb->dev value was ignored and changed before reaching dev_queue_xmit() Fixes: 75c119afe14f ("tcp: implement rb-tree based retransmit queue") Fixes: 28f8bfd1ac94 ("netfilter: Support iif matches in POSTROUTING") Signed-off-by: Eric Dumazet Reported-by: Martin Zaharinov Cc: Florian Westphal Cc: Pablo Neira Ayuso Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/tcp_output.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -1048,6 +1048,10 @@ static int __tcp_transmit_skb(struct soc if (unlikely(!skb)) return -ENOBUFS; + /* retransmit skbs might have a non zero value in skb->dev + * because skb->dev is aliased with skb->rbnode.rb_left + */ + skb->dev = NULL; } inet = inet_sk(sk);