Heap buffer overflow (read) when using $binary_remote_addr with unix sockets

[Maxim Dounin]

Hello!

On Wed, Sep 20, 2017 at 04:21:22PM +0300, Sergey Kandaurov wrote:

> > On 15 Aug 2017, at 13:10, Stephan Dollberg via nginx-devel <nginx-devel at nginx.org> wrote:
> > 
> > Hi,
> > 
> > When using $binary_remote_addr together with unix sockets (without
> > using X-Real-Ip) there is a heap buffer overread of two bytes.
> > 
> > The problem is that we only allocate two bytes for c->sockaddr here
> > http://hg.nginx.org/nginx/file/tip/src/event/ngx_event_accept.c#l167
> > but later on assume it to be of size four
> > http://hg.nginx.org/nginx/file/tip/src/http/ngx_http_variables.c#l1246
> > 
> > 
> 
> Thanks, this is a valid report.
> The reason is that UNIX-domain sockets support
> is not implemented for $binary_remote_addr.
> There are actually more issues, we are working on it.

Fixes for this and related issues committed:

http://hg.nginx.org/nginx/rev/fef61d26da39
http://hg.nginx.org/nginx/rev/874171c3c71a
http://hg.nginx.org/nginx/rev/924b6ef942bf

Thanks.

-- 
Maxim Dounin
http://nginx.org/