Re: Re: [PATCH V2] netfilter: h323: avoid potential attack

[Zhouyi Zhou]

Thanks Eric for replying
> -----Original Messages-----
> From: "Eric Dumazet" <eric.dumazet@xxxxxxxxx>
> Sent Time: Thursday, January 28, 2016
> To: "Zhouyi Zhou" <zhouzhouyi@xxxxxxxxx>
> Cc: pablo@xxxxxxxxxxxxx, kaber@xxxxxxxxx, kadlec@xxxxxxxxxxxxxxxxx, davem@xxxxxxxxxxxxx, netfilter-devel@xxxxxxxxxxxxxxx, coreteam@xxxxxxxxxxxxx, netdev@xxxxxxxxxxxxxxx, linux-kernel@xxxxxxxxxxxxxx, "Zhouyi Zhou" <yizhouzhou@xxxxxxxxx>
> Subject: Re: [PATCH V2] netfilter: h323: avoid potential attack
> 
> On Thu, 2016-01-28 at 16:59 +0800, Zhouyi Zhou wrote:
> > Thanks Eric for your review and advice.
> > 
> > I think hackers chould build a malicious h323 packet to overflow
> > the pointer p which will panic during the memcpy(addr, p, len)
> > 
> > For example, he may fabricate a very large taddr->ipAddress.ip;
> > 
> > Signed-off-by: Zhouyi Zhou <yizhouzhou@xxxxxxxxx>
> > ---
> 
> Except you did not address my feedback about potentially reading not
> initialized memory.
> 
> if the frame length was 1000 bytes, then surely accessing memory at
> offset 8000 will either read garbage, or read data from a prior frame
> and leak secrets.
My patch is intend to prevent kernel panic, to prevent reading garbage
or read data from a prior frame and leak secrets, the prototypes of the 
get_h2x5_addr functions and the functions that call get_h2x5_addr should
be changed, should we do this? 
> 
> 
> 
Cheers 
Zhouyi