From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753794Ab3FYSx4 (ORCPT ); Tue, 25 Jun 2013 14:53:56 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:41151 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752798Ab3FYSeX (ORCPT ); Tue, 25 Jun 2013 14:34:23 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jason Wang , Eric Dumazet , "David S. Miller" Subject: [ 81/95] net_sched: better precise estimation on packet length for untrusted packets Date: Tue, 25 Jun 2013 11:33:08 -0700 Message-Id: <20130625182202.724012020@linuxfoundation.org> X-Mailer: git-send-email 1.8.3.rc0.20.gb99dd2e In-Reply-To: <20130625182153.605455184@linuxfoundation.org> References: <20130625182153.605455184@linuxfoundation.org> User-Agent: quilt/0.60-5.1.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jason Wang [ Upstream commit 15e5a030716468dce4032fa0f398d840fa2756f6 ] gso_segs were reset to zero when kernel receive packets from untrusted source. But we use this zero value to estimate precise packet len which is wrong. So this patch tries to estimate the correct gso_segs value before using it in qdisc_pkt_len_init(). Signed-off-by: Jason Wang Cc: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/core/dev.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) --- a/net/core/dev.c +++ b/net/core/dev.c @@ -2592,6 +2592,7 @@ static void qdisc_pkt_len_init(struct sk */ if (shinfo->gso_size) { unsigned int hdr_len; + u16 gso_segs = shinfo->gso_segs; /* mac layer + network layer */ hdr_len = skb_transport_header(skb) - skb_mac_header(skb); @@ -2601,7 +2602,12 @@ static void qdisc_pkt_len_init(struct sk hdr_len += tcp_hdrlen(skb); else hdr_len += sizeof(struct udphdr); - qdisc_skb_cb(skb)->pkt_len += (shinfo->gso_segs - 1) * hdr_len; + + if (shinfo->gso_type & SKB_GSO_DODGY) + gso_segs = DIV_ROUND_UP(skb->len - hdr_len, + shinfo->gso_size); + + qdisc_skb_cb(skb)->pkt_len += (gso_segs - 1) * hdr_len; } }