Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756261AbaGHTY3 (ORCPT ); Tue, 8 Jul 2014 15:24:29 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:54191 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755706AbaGHTIl (ORCPT ); Tue, 8 Jul 2014 15:08:41 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Michael S. Tsirkin" , "David S. Miller" , "Herbert Xu" Date: Tue, 08 Jul 2014 20:01:50 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 125/125] skbuff: skb_segment: orphan frags before copying In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.249 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.61-rc1 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 --- --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -2698,6 +2698,9 @@ 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); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/