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From: Greg Kroah-Hartman <gregkh@linuxfoundation•org>
To: Florian Westphal <fw@strlen•de>
Cc: peter pi <tiangangpi@gmail•com>, Jan Engelhardt <jengelh@inai•de>,
	Eric Dumazet <eric.dumazet@gmail•com>,
	Greg Hackmann <ghackmann@google•com>,
	Pablo Neira Ayuso <pablo@netfilter•org>,
	Jozsef Kadlecsik <kadlec@blackhole•kfki.hu>,
	Michal Kubecek <mkubecek@suse•cz>,
	netfilter-devel@vger•kernel.org, coreteam@netfilter•org,
	netdev@vger•kernel.org
Subject: Re: [PATCH v2] netfilter: properly initialize xt_table_info structure
Date: Thu, 31 May 2018 12:11:47 +0200	[thread overview]
Message-ID: <20180531101147.GA26342@kroah.com> (raw)
In-Reply-To: <20180531090758.gwvbzpd4iu74yakj@breakpoint.cc>

On Thu, May 31, 2018 at 11:07:58AM +0200, Florian Westphal wrote:
> Greg Kroah-Hartman <gregkh@linuxfoundation•org> wrote:
> > On Thu, May 31, 2018 at 10:24:36AM +0200, Florian Westphal wrote:
> > > peter pi <tiangangpi@gmail•com> wrote:
> > > > Hi Greg, I applied this patch on 4.4 and tested it on my Pixel 2, it seems
> > > > the problem still exists,
> > > 
> > > What is the problem exactly?
> > 
> > The problem is that kernel data is being sent to userspace due to an
> > uncleared buffer that was allocated and then copied to userspace.  This
> > can be reproduced by dumping the current set of iptables rules.  Peter
> > had an example reproducing script that he used to specifically show
> > this.  Peter, can you provide that?
> > 
> > I thought that initializing this buffer to zero would solve the problem,
> > but I guess I cleared the wrong buffer :(
> 
> Never mind, this test was on 4.4 not 4.14.
> 
> But even on 4.14 i don't see how zeroing a buffer that will
> be filled via copy_from_user would help.

It should be copy_to_user() :)

  reply	other threads:[~2018-05-31 10:12 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-17  8:44 [PATCH] netfilter: properly initialize xt_table_info structure Greg Kroah-Hartman
2018-05-17  8:59 ` Michal Kubecek
2018-05-17  9:29   ` Greg Kroah-Hartman
2018-05-17  9:34   ` [PATCH v2] " Greg Kroah-Hartman
2018-05-17  9:55     ` Eric Dumazet
2018-05-17 10:09       ` Greg Kroah-Hartman
2018-05-17 10:42         ` Jan Engelhardt
2018-05-17 13:20           ` Greg Kroah-Hartman
2018-05-18  9:27             ` Florian Westphal
2018-05-18 11:04               ` Greg Kroah-Hartman
2018-05-26 14:54               ` Greg Kroah-Hartman
     [not found]                 ` <CANZU63WyNL4qUJx2eS3gokPMBJLn5=C4-bnOSEF5trX3jGngUA@mail.gmail.com>
2018-05-31  8:24                   ` Florian Westphal
2018-05-31  8:51                     ` Greg Kroah-Hartman
2018-05-31  9:07                       ` Florian Westphal
2018-05-31 10:11                         ` Greg Kroah-Hartman [this message]
     [not found]                       ` <CANZU63VE7fWNL+PJrLp7-5PBS6R6RQPvhw2QgqAK8NhX4uQc9Q@mail.gmail.com>
2018-05-31 11:23                         ` Greg Kroah-Hartman
2018-05-31 11:32                         ` Michal Kubecek
2018-05-31 11:55                           ` Michal Kubecek
2018-05-31 16:25                             ` Greg Kroah-Hartman

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