From patchwork Thu Oct 8 01:21:54 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Cong Wang X-Patchwork-Id: 1378359 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20161025 header.b=PAzAZD4i; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4C6D5l6R4Hz9sTK for ; Thu, 8 Oct 2020 12:24:59 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727895AbgJHBWO (ORCPT ); Wed, 7 Oct 2020 21:22:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48210 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726009AbgJHBWN (ORCPT ); Wed, 7 Oct 2020 21:22:13 -0400 Received: from mail-pf1-x441.google.com (mail-pf1-x441.google.com [IPv6:2607:f8b0:4864:20::441]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4343FC061755 for ; Wed, 7 Oct 2020 18:22:12 -0700 (PDT) Received: by mail-pf1-x441.google.com with SMTP id l126so2616424pfd.5 for ; Wed, 07 Oct 2020 18:22:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=5+wvNeX6adtwcGsxQnaVNp3gmoXBkclIepmj1UUWaJU=; b=PAzAZD4iX2HRszKcX2IHM36Dmd9e/cRfp+FYrcCXAinsVcx8iDhfcGcmQhxpemz25N EVcXRuDYUfKqOURxkBTLCbmOjh3NFY73W4bPpHrssXwdX5LZBLx12T7vO2Oc6TkuStQ6 P3ySrtLtTpNusGodX2znNbvLQceEJKFvE+AXqazX+soljY+Ovoxu/0uWO3W2vmJImjiV gerFYsqNPwiZmBxxvlqEVXshLesIMjgi0x1KA3N5x3BPdu+lFYEfOY0xuwlDlb4MJ9XO pi1rplUEKLJerg4lipn8eu2Eiuz0Q/kjVL8UnnWo+rSjPE5yiVOonLYWAfTLhK/s6HZE 1+nw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=5+wvNeX6adtwcGsxQnaVNp3gmoXBkclIepmj1UUWaJU=; b=DgGZMwRaIUzaONvNOJpioMbnxRlCbMAZARBWgAjMB5rXEgmEO/ZeiWbGuE0J25SSH7 3XG+oBc6lb4HlRF/ctoc09Ty8gJ0S8eh2d2mhL5k277j+m2bIvqRubcL2tacbVXTAzZQ g2tHxLgUk1MSvr/Enj3oiIyASi/X4wmmPwHZYBdglaaBe4aS4j3NsEedxlDg5jPn1gnL /52ZTyuHHb78rIhLPuCwxxHgMuddvhbJTmQ7Get7D0ZKlgCMiSJBMC386uzE178+scwU vsCCrIheHripnDWLnJixF3/wIy6d3gnpvXx/VRazpkI4r8f5lXEzAntaqAYh9q7IFpu9 RlHw== X-Gm-Message-State: AOAM533c3RvVwCMPBl4PeB27U+Jgmx3dnQwQEkPX14VUYm3nTqgXw8Sv Mh3+JzbSb+XAgN+mNYUZ3JyWQvVrvBlvQg== X-Google-Smtp-Source: ABdhPJzbsFeTVIj6Zm49dFE43KUZx9npD4Zj9cv7qpaWYOE84dsQovQXUu5Qq+s1a+QALQTg46A7RA== X-Received: by 2002:aa7:9501:0:b029:155:3b11:d5c4 with SMTP id b1-20020aa795010000b02901553b11d5c4mr1851015pfp.76.1602120131390; Wed, 07 Oct 2020 18:22:11 -0700 (PDT) Received: from unknown.linux-6brj.site ([2600:1700:65a0:ab60::46]) by smtp.gmail.com with ESMTPSA id u7sm4627667pfn.37.2020.10.07.18.22.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 07 Oct 2020 18:22:10 -0700 (PDT) From: Cong Wang To: netdev@vger.kernel.org Cc: Cong Wang , syzbot+4a2c52677a8a1aa283cb@syzkaller.appspotmail.com, William Tu , Willem de Bruijn Subject: [Patch net] ip_gre: set dev->hard_header_len properly Date: Wed, 7 Oct 2020 18:21:54 -0700 Message-Id: <20201008012154.11149-1-xiyou.wangcong@gmail.com> X-Mailer: git-send-email 2.28.0 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org GRE tunnel has its own header_ops, ipgre_header_ops, and sets it conditionally. When it is set, it assumes the outer IP header is already created before ipgre_xmit(). This is not true when we send packets through a raw packet socket, where L2 headers are supposed to be constructed by user. Packet socket calls dev_validate_header() to validate the header. But GRE tunnel does not set dev->hard_header_len, so that check can be simply bypassed, therefore uninit memory could be passed down to ipgre_xmit(). Fix this by setting dev->hard_header_len whenever sets header_ops, as dev->hard_header_len is supposed to be the length of the header created by dev->header_ops->create() anyway. Reported-and-tested-by: syzbot+4a2c52677a8a1aa283cb@syzkaller.appspotmail.com Cc: William Tu Cc: Willem de Bruijn Signed-off-by: Cong Wang Acked-by: Willem de Bruijn --- net/ipv4/ip_gre.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c index 4e31f23e4117..43b62095559e 100644 --- a/net/ipv4/ip_gre.c +++ b/net/ipv4/ip_gre.c @@ -987,10 +987,12 @@ static int ipgre_tunnel_init(struct net_device *dev) return -EINVAL; dev->flags = IFF_BROADCAST; dev->header_ops = &ipgre_header_ops; + dev->hard_header_len = tunnel->hlen + sizeof(*iph); } #endif } else if (!tunnel->collect_md) { dev->header_ops = &ipgre_header_ops; + dev->hard_header_len = tunnel->hlen + sizeof(*iph); } return ip_tunnel_init(dev);