Re: CVE request - kernel: nfsd4: bug in read_buf

[Josh Bressers <bressers () redhat com>]

Please use CVE-2010-2521

Thanks.

-- 
    JB


----- "Eugene Teo" <eugeneteo () kernel sg> wrote:

> https://bugzilla.redhat.com/show_bug.cgi?id=612028
> Upstream commit: http://git.kernel.org/linus/2bc3c117
>
> Introduced in commit 89fc0a31 ( v2.5.49) and 099e99f0 (v2.6.0-test3).
>
> Fixed in v2.6.34-rc6.
>
> "When read_buf is called to move over to the next page in the pagelist
>
> of an NFSv4 request, it sets argp->end to essentially a random number,
>
> certainly not an address within the page which argp->p now points to.
>
> So subsequent calls to READ_BUF will think there is much more than a 
> page of spare space (the cast to u32 ensures an unsigned comparison)
> so 
> we can expect to fall off the end of the second page."
>
> There's a possibility of triggering this with a specially crafted NFS
>
> WRITE request (if accepted by the server).
>
> Thanks, Eugene
> -- 
> main(i) { putchar(182623909 >> (i-1) * 5&31|!!(i<7)<<6) && main(++i);
> }