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=-10.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,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 595E3C433DF for ; Wed, 26 Aug 2020 12:07:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 33BF720838 for ; Wed, 26 Aug 2020 12:07:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598443676; bh=CWyMEWvEF4mgTZYLBmO4vAIk8fL1sXzxh/kZHfgo1s0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=a9TQNI6MIVI3+LRaoMIPnWZlAe/b8Z3L9xr+obEBZTtvewRdnNAYJEkfVSEjYahZT +3GVpzr7qcFEJw6WfGEQYV6djWBmkDF+f1YmjZdADLo22dMnrxRNG6iuqZy6wsHkZy MxXbUEeb8M3pquyH6Cw9cqth+AM7wylkYg2ROENY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729559AbgHZMHy (ORCPT ); Wed, 26 Aug 2020 08:07:54 -0400 Received: from mail.kernel.org ([198.145.29.99]:36778 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729457AbgHZMCk (ORCPT ); Wed, 26 Aug 2020 08:02:40 -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 9959120786; Wed, 26 Aug 2020 12:02:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598443360; bh=CWyMEWvEF4mgTZYLBmO4vAIk8fL1sXzxh/kZHfgo1s0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qmcUQCB5imzfV6A6e5Fo26qhzmHNEXiVaBi2t4QlXay9//zTsevCIpRnqs3khtThn YyxK1O8Ta8mlFUUnBdwQ/ZjclobTGMZBGK4EhGc5axsUb9vNyWmIGfhkV2SegtPq0l mcZwqUh3b5tr+z4vzPKcwxksfgSpMKT8XW0V0THY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Miaohe Lin , "David S. Miller" Subject: [PATCH 5.7 02/15] net: Fix potential wrong skb->protocol in skb_vlan_untag() Date: Wed, 26 Aug 2020 14:02:30 +0200 Message-Id: <20200826114849.419802836@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200826114849.295321031@linuxfoundation.org> References: <20200826114849.295321031@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: Miaohe Lin [ Upstream commit 55eff0eb7460c3d50716ed9eccf22257b046ca92 ] We may access the two bytes after vlan_hdr in vlan_set_encap_proto(). So we should pull VLAN_HLEN + sizeof(unsigned short) in skb_vlan_untag() or we may access the wrong data. Fixes: 0d5501c1c828 ("net: Always untag vlan-tagged traffic on input.") Signed-off-by: Miaohe Lin Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/core/skbuff.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -5421,8 +5421,8 @@ struct sk_buff *skb_vlan_untag(struct sk skb = skb_share_check(skb, GFP_ATOMIC); if (unlikely(!skb)) goto err_free; - - if (unlikely(!pskb_may_pull(skb, VLAN_HLEN))) + /* We may access the two bytes after vlan_hdr in vlan_set_encap_proto(). */ + if (unlikely(!pskb_may_pull(skb, VLAN_HLEN + sizeof(unsigned short)))) goto err_free; vhdr = (struct vlan_hdr *)skb->data;