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=-5.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS, T_DKIMWL_WL_HIGH,URIBL_BLOCKED,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 80692C04A6B for ; Mon, 6 May 2019 14:44:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 573492053B for ; Mon, 6 May 2019 14:44:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1557153855; bh=UIHC9Cy2fpk/qppWUPfyau/uOaITclXHx0K+EQfW83s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=i6vEqxEhnvnSUV0bwouhwHue/mHVWo1gGngXTu6F3HTWDkEmNQ14LDK6cDhEnFyWU WNqX6oYwy//oSRuANDx4QtOrjeU4dl6k+2aGmP0g6F1Oq3c7gsGSXt6Svn6j0FpY+d TlZoPUJwHShL1Kb/8LFU+YWsgaSW9tXx9c1CN9YE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726760AbfEFOoN (ORCPT ); Mon, 6 May 2019 10:44:13 -0400 Received: from mail.kernel.org ([198.145.29.99]:40258 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727654AbfEFOoL (ORCPT ); Mon, 6 May 2019 10:44:11 -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 B3BF3214AF; Mon, 6 May 2019 14:44:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1557153850; bh=UIHC9Cy2fpk/qppWUPfyau/uOaITclXHx0K+EQfW83s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gITQZ2APY/OEabH4bZ9BG30UDEUWz5lPGmpmemhey0VLlSk0inWqq6TABvvMmkHUj KFOIco/4pcMHzfoCrL2PMgvDN4kOT1GkPMKPLWb5pJIl2cyjUQmJps2N75AIkK9egm MO/M0PVPBq5NHeBd8sgvjYDvMGqsU4lUSTZcnxTw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Shmulik Ladkani , "David S. Miller" Subject: [PATCH 4.14 02/75] ipv4: ip_do_fragment: Preserve skb_iif during fragmentation Date: Mon, 6 May 2019 16:32:10 +0200 Message-Id: <20190506143053.481001390@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190506143053.287515952@linuxfoundation.org> References: <20190506143053.287515952@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Shmulik Ladkani [ Upstream commit d2f0c961148f65bc73eda72b9fa3a4e80973cb49 ] Previously, during fragmentation after forwarding, skb->skb_iif isn't preserved, i.e. 'ip_copy_metadata' does not copy skb_iif from given 'from' skb. As a result, ip_do_fragment's creates fragments with zero skb_iif, leading to inconsistent behavior. Assume for example an eBPF program attached at tc egress (post forwarding) that examines __sk_buff->ingress_ifindex: - the correct iif is observed if forwarding path does not involve fragmentation/refragmentation - a bogus iif is observed if forwarding path involves fragmentation/refragmentatiom Fix, by preserving skb_iif during 'ip_copy_metadata'. Signed-off-by: Shmulik Ladkani Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/ip_output.c | 1 + 1 file changed, 1 insertion(+) --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -518,6 +518,7 @@ static void ip_copy_metadata(struct sk_b to->pkt_type = from->pkt_type; to->priority = from->priority; to->protocol = from->protocol; + to->skb_iif = from->skb_iif; skb_dst_drop(to); skb_dst_copy(to, from); to->dev = from->dev;