[BUG] New memory invalid read regression in resolver since nginx 1.7.5

[Maxim Dounin]

Hello!

On Tue, Sep 30, 2014 at 03:10:42PM -0700, Yichun Zhang (agentzh) wrote:

> Hello!
> 
> I've noticed that the code re-factoring in the resolver in nginx 1.7.5
> introduces a new regression that can cause memory invalid reads when
> --with-debug is used to build the nginx. The issue still exists in
> nginx 1.7.6.

[...]

>     ngx_log_debug2(NGX_LOG_DEBUG_EVENT, ev->log, 0,
>                    "event timer del: %d: %M",
>                     ngx_event_ident(ev->data), ev->timer.key);
> 
> while ev->data here is the resolver node that has already been freed
> up earlier in ngx_resolver_free_node.

Yes, thanks, it's known (though mostly harmless) issue.
Ruslan is looking into it.

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