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=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 AA066C04A6B for ; Mon, 6 May 2019 14:53:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 71A0D2053B for ; Mon, 6 May 2019 14:53:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1557154394; bh=E3pP6r+Tt7mCCHRSN5hTQTQRqAJ1nkxxBBX51vIGfwc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=oxMEVm3bYq784OS4JnANVCaQzZI6b3j4HKhaRmpx4/cM2ju0ddsutm5EqMVd/Kx4X OiBkQKwas/QOuALiiLYdwCoqq1EtZY0sv9n0xOeyJGHOguJ7Rcz+LCDFgux4C5ipuL qaQwVUiDeDqusbR6/IXo17FMKabI+sieSVe/hW70= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728866AbfEFOrj (ORCPT ); Mon, 6 May 2019 10:47:39 -0400 Received: from mail.kernel.org ([198.145.29.99]:46834 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728555AbfEFOrc (ORCPT ); Mon, 6 May 2019 10:47:32 -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 91CF921019; Mon, 6 May 2019 14:47:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1557154052; bh=E3pP6r+Tt7mCCHRSN5hTQTQRqAJ1nkxxBBX51vIGfwc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CiUUysFIgrI4scrfxs8IuPGjv/KPrvqh2vx0QPjBHmt0mOD3BTXXXOZTbKpnu22Pg H8UoH9dmxwlSxn8sW9jGYigx98LtMLPdFD+ddkt17qQ34686B3BLIk9QqzCB4QFui/ sq1fVgr0YEvFChskALNuASNUaXCsriiKi6oER+nI= 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 4.9 02/62] ipv4: ip_do_fragment: Preserve skb_iif during fragmentation Date: Mon, 6 May 2019 16:32:33 +0200 Message-Id: <20190506143051.313171027@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190506143051.102535767@linuxfoundation.org> References: <20190506143051.102535767@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 @@ -492,6 +492,7 @@ 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;