From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757932AbaF1TSv (ORCPT ); Sat, 28 Jun 2014 15:18:51 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:52866 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753695AbaF1Rrd (ORCPT ); Sat, 28 Jun 2014 13:47:33 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Michael S. Tsirkin" , Herbert Xu , "David S. Miller" , Ben Hutchings Subject: [PATCH 3.4 37/43] skbuff: skb_segment: orphan frags before copying Date: Sat, 28 Jun 2014 10:46:28 -0700 Message-Id: <20140628174451.490679776@linuxfoundation.org> X-Mailer: git-send-email 2.0.1 In-Reply-To: <20140628174449.788784511@linuxfoundation.org> References: <20140628174449.788784511@linuxfoundation.org> User-Agent: quilt/0.63-1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: "Michael S. Tsirkin" commit 1fd819ecb90cc9b822cd84d3056ddba315d3340f upstream. skb_segment copies frags around, so we need to copy them carefully to avoid accessing user memory after reporting completion to userspace through a callback. skb_segment doesn't normally happen on datapath: TSO needs to be disabled - so disabling zero copy in this case does not look like a big deal. Signed-off-by: Michael S. Tsirkin Acked-by: Herbert Xu Signed-off-by: David S. Miller [bwh: Backported to 3.2. As skb_segment() only supports page-frags *or* a frag list, there is no need for the additional frag_skb pointer or the preparatory renaming.] Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman --- net/core/skbuff.c | 3 +++ 1 file changed, 3 insertions(+) --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -2777,6 +2777,9 @@ struct sk_buff *skb_segment(struct sk_bu skb_put(nskb, hsize), hsize); while (pos < offset + len && i < nfrags) { + if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC))) + goto err; + *frag = skb_shinfo(skb)->frags[i]; __skb_frag_ref(frag); size = skb_frag_size(frag);