Re: CVE-2014-0196: Linux kernel pty layer race condition memory corruption

[Shawn <citypw () gmail com>]

Workable PoC:
http://pastebin.com/yTSFUBgZ

On Mon, May 5, 2014 at 6:08 PM, Marcus Meissner <meissner () suse de> wrote:
> Hi,
>
> SUSE customer Ericsson reported a kernel crash to us which turned out
> to be a race condition in the PTY write buffer handling.
>
> When two processes/threads write to the same pty, the buffer end could
> be overwritten and so memory corruption into adjacent buffers could lead
> to crashes / code execution.
>
> Jiri Slaby and Peter Hurley localized and fixed this problem.
>
> CVE-2014-0196 has been assigned to this issue.
>
> Jiri thinks this was introduced during 2.6.31 development by
> d945cb9cce20ac7143c2de8d88b187f62db99bdc (pty: Rework the pty
> layer to use the normal buffering logic) in 2.6.31-rc3. Until then, pty
> was writing directly to a line discipline without using buffers.
>
> https://bugzilla.novell.com/show_bug.cgi?id=875690
>
> Patch is also attached.
>
> Ciao, Marcus



-- 
GNU powered it...
GPL protect it...
God blessing it...

regards
Shawn