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=-10.0 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 7F656C433E2 for ; Tue, 1 Sep 2020 17:24:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5B61D2078B for ; Tue, 1 Sep 2020 17:24:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598981069; bh=Ogk8MZaDBf4JA0gbv2X0/yg77BbapuRkk1sa2XyGvMM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=kh4r655vPN82jnuPOSrUqIFRVkqLOWslq5h3FMbhpzq1WsbxkDwGCGQ4dYFwouKek mVh0RqCnEiAjscCT9YrQourqJDBR9KWbXk8gaCb7Ucr55qK1pLoixkdJpuY6yIZtiA wT66f6fTm1DCHxYborUBLpWh3AloGhOI7VKrSbYA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731901AbgIARY0 (ORCPT ); Tue, 1 Sep 2020 13:24:26 -0400 Received: from mail.kernel.org ([198.145.29.99]:53736 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726285AbgIAPLq (ORCPT ); Tue, 1 Sep 2020 11:11:46 -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 CA9AF2078B; Tue, 1 Sep 2020 15:11:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598973105; bh=Ogk8MZaDBf4JA0gbv2X0/yg77BbapuRkk1sa2XyGvMM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=h2fTKaBj793ZIysRJ21PbkiGeoDQVyCy7WHJF5bt9cRRdLz1meJC/1LlBNGCvmt9p dH8Jx05qBEa4YmUSsYbghkqxKLKjXIltppFDeUaiNGQzSz7mqIg1igBRn39Tpho0rn h1cZwFE7fC8dG7fuKy+lWxKFBbxSh6srRdzctK44= 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 4.4 01/62] net: Fix potential wrong skb->protocol in skb_vlan_untag() Date: Tue, 1 Sep 2020 17:09:44 +0200 Message-Id: <20200901150920.786123163@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200901150920.697676718@linuxfoundation.org> References: <20200901150920.697676718@linuxfoundation.org> User-Agent: quilt/0.66 X-stable: review X-Patchwork-Hint: ignore 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 @@ -4370,8 +4370,8 @@ 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;