Re: CVE Request: glibc getaddrinfo() stack overflow

[Marcus Meissner <meissner () suse de>]

On Wed, Apr 03, 2013 at 01:10:21PM +0200, Marcus Meissner wrote:
> Hi,
>
> A customer reported a glibc crash, which turned out to be a stack overflow in
> getaddrinfo().
>
> getaddrinfo() uses:
>       struct sort_result results[nresults];
> with nresults controlled by the nameservice chain (DNS or /etc/hosts).
>
> This will be visible mostly on threaded applications with smaller stacksizes,
> or operating near out of stack.
>
> Reproducer I tried:
>       $ for i in `seq 1 10000000`; do echo "ff00::$i a1" >>/etc/hosts; done
>       $ ulimit -s 1024
>       $ telnet a1
>       Segmentation fault
>       (clean out /etc/hosts again )
>
>
> I am not sure you can usually push this amount of addresses via DNS for all
> setups.
>
> Andreas is currently pushing the patch to glibc GIT.
>
> Reference:
> https://bugzilla.novell.com/show_bug.cgi?id=813121

Upstream GLIBC commit is:
http://sourceware.org/git/?p=glibc.git;a=commit;h=1cef1b19089528db11f221e938f60b9b048945d7

Ciao, Marcus