From patchwork Tue Sep 1 15:09:39 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 264448 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=-10.0 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,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 617CFC433E2 for ; Tue, 1 Sep 2020 17:14:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 38E4E207D3 for ; Tue, 1 Sep 2020 17:14:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598980487; bh=7/WCKlMTvBR7YmWfYFwJp9dRNVnCi7LtZNSvGah06qg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=WWF5EcuTwDc3dE44p69slYHY/hBCAgeg8DVo2lsTDg+OvG8BpUrzDvS/lQ2wcKk4q 5O7S7mXDkSeBmqA3hvdhsEnkxY1pGw8Nt/MkLdu1hBp9pObHwrOF+QwDS/DdAxp7KE FNuKsO4U2dHqGL+JOD4vaNptO8UXsfBAnagzBC/E= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729189AbgIAPPP (ORCPT ); Tue, 1 Sep 2020 11:15:15 -0400 Received: from mail.kernel.org ([198.145.29.99]:59348 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729185AbgIAPPJ (ORCPT ); Tue, 1 Sep 2020 11:15:09 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (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 45CC1206FA; Tue, 1 Sep 2020 15:15:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598973308; bh=7/WCKlMTvBR7YmWfYFwJp9dRNVnCi7LtZNSvGah06qg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iQtQPnYsP0rLd9WQEy+KUWrLxkEwyTAiK3QprMs07CAUCsbrNPyDbG1SW+sI+XfzT lvwEyGZSnrJQ4zIqFGAtimuvLc5QlKD4rr1lDPlHAm0fI0PEkl39ywcQNHmxdPgxe0 xwAbM67SiH99dbLZ8das6DgR1blUNN4rrnwN/wM0= 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 4.9 03/78] net: Fix potential wrong skb->protocol in skb_vlan_untag() Date: Tue, 1 Sep 2020 17:09:39 +0200 Message-Id: <20200901150924.884408213@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200901150924.680106554@linuxfoundation.org> References: <20200901150924.680106554@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@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 @@ -4591,8 +4591,8 @@ 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;