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=-6.8 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 93048C0650F for ; Thu, 8 Aug 2019 19:14:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 58AE32173E for ; Thu, 8 Aug 2019 19:14:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1565291672; bh=M7XPlP18xX9EyFM2/Zr9JE6n+F1kWYYW82vo+vdquDI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=jZ109F3y09iXoCwFAVFLuNi7dgwoX8RDHht08nkEYF43gx+QG0qmBNIoUQ0IuUgux qiZeeJwo3L1IBL6ddDLTjDMEHt1gSSZfBUWI+dcGcCUbbOmYXojquDNMNX6vTDUALm zFFyP1bYFctLqypwnWpCKWi8Pvx1I5RqdCLZuMrc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404875AbfHHTIT (ORCPT ); Thu, 8 Aug 2019 15:08:19 -0400 Received: from mail.kernel.org ([198.145.29.99]:42284 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404852AbfHHTIP (ORCPT ); Thu, 8 Aug 2019 15:08:15 -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 76B0D218C9; Thu, 8 Aug 2019 19:08:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1565291295; bh=M7XPlP18xX9EyFM2/Zr9JE6n+F1kWYYW82vo+vdquDI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Prcm0I20cG82p1RNqysB+A4Sr0ERJWHGrs+jAID1CuZTf9hcmkwafoPr86O+DgLzX ltTlYLMVi4iLX5wgJOoDKKUsQHYPY2cLQO8P2EtrNIMZWtmq50hhR5x7MnxFan6x0r nqVUj+yu5OnzJZnk7D5UfU+pK3xUMCxxyG1vIaFI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Brandon Cazander , Jesper Dangaard Brouer , "David S. Miller" Subject: [PATCH 5.2 45/56] net: fix bpf_xdp_adjust_head regression for generic-XDP Date: Thu, 8 Aug 2019 21:05:11 +0200 Message-Id: <20190808190454.955968164@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190808190452.867062037@linuxfoundation.org> References: <20190808190452.867062037@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: Jesper Dangaard Brouer [ Upstream commit 065af355470519bd184019a93ac579f22b036045 ] When generic-XDP was moved to a later processing step by commit 458bf2f224f0 ("net: core: support XDP generic on stacked devices.") a regression was introduced when using bpf_xdp_adjust_head. The issue is that after this commit the skb->network_header is now changed prior to calling generic XDP and not after. Thus, if the header is changed by XDP (via bpf_xdp_adjust_head), then skb->network_header also need to be updated again. Fix by calling skb_reset_network_header(). Fixes: 458bf2f224f0 ("net: core: support XDP generic on stacked devices.") Reported-by: Brandon Cazander Signed-off-by: Jesper Dangaard Brouer Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/core/dev.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4382,12 +4382,17 @@ static u32 netif_receive_generic_xdp(str act = bpf_prog_run_xdp(xdp_prog, xdp); + /* check if bpf_xdp_adjust_head was used */ off = xdp->data - orig_data; - if (off > 0) - __skb_pull(skb, off); - else if (off < 0) - __skb_push(skb, -off); - skb->mac_header += off; + if (off) { + if (off > 0) + __skb_pull(skb, off); + else if (off < 0) + __skb_push(skb, -off); + + skb->mac_header += off; + skb_reset_network_header(skb); + } /* check if bpf_xdp_adjust_tail was used. it can only "shrink" * pckt.