Re: [PATCH] CVE-2015-7547 --- glibc getaddrinfo() stack-based buffer overflow

[Mike Frysinger <vapier at gentoo dot org>]

On 16 Feb 2016 13:24, Carlos O'Donell wrote:
> >> --- a/resolv/res_send.c
> >> +++ b/resolv/res_send.c
> >>  
> >> +   Please also note that for TCP we send both queries over the same
> >> +   socket one after another.  This technically violates best practice
> >> +   since the server is allowed to read the first query, respond, and
> >> +   then close the socket (to service another client).  If the server
> >> +   does this, then the remaining second query in the socket data buffer
> >> +   will cause the server to send the client an RST which will arrive
> >> +   asynchronously and the client's OS will likely tear down the socket
> >> +   receive buffer resulting in a potentially short read and lost
> >> +   response data.  This will force the client to retry the query again,
> >> +   and this process may repeat until all servers and connection resets
> >> +   are exhausted and then the query will fail.  It's not known if this
> >> +   happens with any frequency in real DNS server implementations.  This
> >> +   implementation should be corrected to use two sockets by default for
> >> +   parallel queries.
> > 
> > should we open a bug now for this ?
> 
> Yes. Would you mind helping with that?

https://sourceware.org/bugzilla/show_bug.cgi?id=19646
-mike

Attachment: signature.asc
Description: Digital signature