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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 369CBC33CAF for ; Thu, 16 Jan 2020 18:46:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 092C320661 for ; Thu, 16 Jan 2020 18:46:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579200383; bh=GxpxSfn4Aog9jObkkwzJClYhMneNU3fTJqn+IXbCiGo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=lcfvLjDzjI1CXLgZY5tVLwqnLoq46wLLN5E2+AEz7JuqsXsHPMrfApuDAM4zrJuVf qbVnfN/21yfsKhY8ks1tnMZBhJs0Qy6bMcYpTvbu1Zl22qJY7PWIp179HFnMHnw/sm 6uDavoL76hSwHOnu5ZZEmw1yraAgYv0HQaGYrx/U= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389874AbgAPRKX (ORCPT ); Thu, 16 Jan 2020 12:10:23 -0500 Received: from mail.kernel.org ([198.145.29.99]:48412 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389911AbgAPRKX (ORCPT ); Thu, 16 Jan 2020 12:10:23 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3B356205F4; Thu, 16 Jan 2020 17:10:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579194622; bh=GxpxSfn4Aog9jObkkwzJClYhMneNU3fTJqn+IXbCiGo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Wyz+O5Rwk/jbC8uaAyi+p+7sltSdczBBFyYQEAZ9cSDrEjrm3czSklo4fgikssVbQ uFK52lkIgZ4Cv4p3oIVftIMLGNRGO8dfzkOJsXi5VdUZpmMlKaoo1qJVaaSEhUah66 qckkt7DThFaicMLB7iDYDm5RlT8fMqtANF+saWjQ= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Jesper Dangaard Brouer , Brandon Cazander , "David S . Miller" , Sasha Levin , netdev@vger.kernel.org, bpf@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 483/671] net: fix bpf_xdp_adjust_head regression for generic-XDP Date: Thu, 16 Jan 2020 12:02:01 -0500 Message-Id: <20200116170509.12787-220-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200116170509.12787-1-sashal@kernel.org> References: <20200116170509.12787-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@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: Sasha Levin --- net/core/dev.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/net/core/dev.c b/net/core/dev.c index 935fe158cfaf..73ebacabfde8 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4349,12 +4349,17 @@ static u32 netif_receive_generic_xdp(struct sk_buff *skb, 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. -- 2.20.1