Hi James,
Any chance this can get into security-next as well? It'll need to go
back to stable, but it's a small enough corner-case that I don't mind
it not landing in 3.6 directly. I'm happy if it gets into 3.6.x stable
at some point.
Thanks!
-Kees
On Mon, Aug 27, 2012 at 11:38 AM, Kees Cook <keesc...@chromium.org> wrote:
> When running a 64-bit kernel and receiving prctls from a 32-bit
> userspace, the "-1" used as an unsigned long will end up being
> misdetected. The kernel is looking for 0xffffffffffffffff instead of
> 0xffffffff. Since prctl lacks a distinct compat interface, Yama needs
> to handle this translation itself. As such, support either value as
> meaning PR_SET_PTRACER_ANY, to avoid breaking the ABI for 64-bit.
>
> Signed-off-by: Kees Cook <keesc...@chromium.org>
> Cc: sta...@vger.kernel.org
> ---
> security/yama/yama_lsm.c | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/security/yama/yama_lsm.c b/security/yama/yama_lsm.c
> index 0cc99a3..dcd6178 100644
> --- a/security/yama/yama_lsm.c
> +++ b/security/yama/yama_lsm.c
> @@ -143,7 +143,7 @@ static int yama_task_prctl(int option, unsigned long
> arg2, unsigned long arg3,
> if (arg2 == 0) {
> yama_ptracer_del(NULL, myself);
> rc = 0;
> - } else if (arg2 == PR_SET_PTRACER_ANY) {
> + } else if (arg2 == PR_SET_PTRACER_ANY || (int)arg2 == -1) {
> rc = yama_ptracer_add(NULL, myself);
> } else {
> struct task_struct *tracer;
> --
> 1.7.0.4
>
>
> --
> Kees Cook
> Chrome OS Security
--
Kees Cook
Chrome OS Security
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