Re: [PATCH] signal: stop info leak via the tkill and the tgkillsyscalls

From: Serge E. Hallyn
Date: Sat Apr 20 2013 - 18:14:08 EST


Quoting Kees Cook (keescook@xxxxxxxxxxxx):
> From: Emese Revfy <re.emese@xxxxxxxxx>
>
> 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@xxxxxxxxx>

Sorry, not sure if this is applied yet,

Acked-by: Serge Hallyn <serge.hallyn@xxxxxxxxxxxxx>

> Reviewed-by: PaX Team <pageexec@xxxxxxxxxxx>
> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> ---
> kernel/signal.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/signal.c b/kernel/signal.c
> index dd72567..598dc06 100644
> --- a/kernel/signal.c
> +++ b/kernel/signal.c
> @@ -2948,7 +2948,7 @@ 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;
> --
> 1.7.9.5
>
> --
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