[Acked] [Lucid][CVE-2013-2141] kernel/signal.c: stop info leak via the tkill and the tgkill syscalls

[Andy Whitcroft]

On Thu, Jun 20, 2013 at 12:31:29PM +0100, Luis Henriques wrote:
> From: Emese Revfy <re.emese at gmail.com>
> 
> BugLink: https://bugs.launchpad.net/bugs/1187732
> 
> CVE-2013-2141
> 
> This fixes a kernel memory contents leak via the tkill and tgkill syscalls
> for compat processes.
> 
> This is visible in the siginfo_t->_sifields._rt.si_sigval.sival_ptr field
> when handling signals delivered from tkill.
> 
> The place of the infoleak:
> 
> int copy_siginfo_to_user32(compat_siginfo_t __user *to, siginfo_t *from)
> {
>         ...
>         put_user_ex(ptr_to_compat(from->si_ptr), &to->si_ptr);
>         ...
> }
> 
> Signed-off-by: Emese Revfy <re.emese at gmail.com>
> Reviewed-by: PaX Team <pageexec at freemail.hu>
> Signed-off-by: Kees Cook <keescook at chromium.org>
> Cc: Al Viro <viro at zeniv.linux.org.uk>
> Cc: Oleg Nesterov <oleg at redhat.com>
> Cc: "Eric W. Biederman" <ebiederm at xmission.com>
> Cc: Serge Hallyn <serge.hallyn at canonical.com>
> Cc: <stable at vger.kernel.org>
> Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
> Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
> (cherry picked from commit b9e146d8eb3b9ecae5086d373b50fa0c1f3e7f0f)
> 
> Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
> ---
>  kernel/signal.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/kernel/signal.c b/kernel/signal.c
> index 1c6675b..fb7e242 100644
> --- a/kernel/signal.c
> +++ b/kernel/signal.c
> @@ -2301,7 +2301,7 @@ do_send_specific(pid_t tgid, pid_t pid, int sig, struct siginfo *info)
>  
>  static int do_tkill(pid_t tgid, pid_t pid, int sig)
>  {
> -	struct siginfo info;
> +	struct siginfo info = {};
>  
>  	info.si_signo = sig;
>  	info.si_errno = 0;
> -- 
> 1.8.1.2
> 
> -- 
> kernel-team mailing list
> kernel-team at lists.ubuntu.com
> https://lists.ubuntu.com/mailman/listinfo/kernel-team

Matches upstream and looks to do what is claimed.

Acked-by: Andy Whitcroft <apw at canonical.com>

That this is only for lucid, does that imply we are getting the rest via
stable?

-apw