From: Stephen Hemminger <stephen@networkplumber.org>
To: "Hu, Jiayu" <jiayu.hu@intel.com>
Cc: "Richardson, Bruce" <bruce.richardson@intel.com>,
"dev@dpdk.org" <dev@dpdk.org>, "Bie, Tiwei" <tiwei.bie@intel.com>,
"stable@dpdk.org" <stable@dpdk.org>
Subject: Re: [dpdk-dev] [PATCH] gro: fix overflow of TCP Options length calculation
Date: Mon, 7 Jan 2019 22:19:18 -0800 [thread overview]
Message-ID: <20190107221918.1db62f1b@hermes.lan> (raw)
In-Reply-To: <ED946F0BEFE0A141B63BABBD629A2A9B3CF3E117@shsmsx102.ccr.corp.intel.com>
On Tue, 8 Jan 2019 01:22:18 +0000
"Hu, Jiayu" <jiayu.hu@intel.com> wrote:
> > -----Original Message-----
> > From: Richardson, Bruce
> > Sent: Monday, January 7, 2019 10:30 PM
> > To: Hu, Jiayu <jiayu.hu@intel.com>
> > Cc: dev@dpdk.org; Bie, Tiwei <tiwei.bie@intel.com>; stable@dpdk.org
> > Subject: Re: [dpdk-dev] [PATCH] gro: fix overflow of TCP Options length
> > calculation
> >
> > On Fri, Jan 04, 2019 at 09:57:16AM +0800, Jiayu Hu wrote:
> > > If we receive a packet with an invalid TCP header, whose
> > > TCP header length is less than 20 bytes (the minimal TCP
> > > header length), the calculated TCP Options length will
> > > overflow and result in incorrect reassembly behaviors.
> >
> > Please explain how changing the "len" type fixes this behaviour.
>
> Originally, 'uint16_t len = RTE_MAX(tcp_hl, tcp_hl_orig) - sizeof(struct tcp_hdr)'.
> When the TCP header length of an input packet is less than 20, which is the value of
> sizeof(struct tcp_hdr), the value of len will overflow. For example, if TCP header lengths
> of input packets are 14, the value of 'len' will be 65529 (65535-6). After then, we will
> compare TCP options via memcmp(tcp_hdr+1,..., len), which would cause segment fault.
For future safety, GRO should check header lengths for IP and TCP before looking
at packet. It is basic structure hygiene
next prev parent reply other threads:[~2019-01-08 6:19 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-04 1:57 Jiayu Hu
2019-01-07 14:29 ` Bruce Richardson
2019-01-08 1:22 ` Hu, Jiayu
2019-01-08 6:19 ` Stephen Hemminger [this message]
2019-01-08 6:08 ` [dpdk-dev] [PATCH] gro: add missing invalid packet checks Jiayu Hu
2019-01-08 6:31 ` Stephen Hemminger
2019-01-08 8:14 ` Hu, Jiayu
2019-01-08 10:39 ` Ananyev, Konstantin
2019-01-08 11:33 ` Morten Brørup
2019-01-08 13:40 ` Hu, Jiayu
2019-01-08 13:43 ` Ananyev, Konstantin
2019-01-08 14:50 ` Morten Brørup
2019-01-09 3:32 ` Hu, Jiayu
2019-01-10 15:06 ` [dpdk-dev] [PATCH v2] " Jiayu Hu
2019-01-14 22:26 ` [dpdk-dev] [dpdk-stable] " Thomas Monjalon
2019-01-15 1:00 ` [dpdk-dev] " Stephen Hemminger
2019-01-15 2:48 ` Hu, Jiayu
2019-01-15 5:05 ` Wang, Yinan
2019-01-15 10:11 ` Ananyev, Konstantin
2019-01-15 12:18 ` Hu, Jiayu
2019-01-15 13:38 ` Hu, Jiayu
2019-01-16 0:45 ` [dpdk-dev] [PATCH v3] gro: add missing invalid TCP header length check Jiayu Hu
2019-01-16 9:49 ` Ananyev, Konstantin
2019-01-17 21:41 ` Thomas Monjalon
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