On Mon, 28 Aug 2023 17:08:56 +0200 Florent Revest revest@chromium.org wrote:
Defining a prctl flag as an int is a footgun because on a 64 bit machine and with a variadic implementation of prctl (like in musl and glibc), when used directly as a prctl argument, it can get casted to long with garbage upper bits which would result in unexpected behaviors.
This patch changes the constant to an unsigned long to eliminate that possibilities. This does not break UAPI.
Fixes: b507808ebce2 ("mm: implement memory-deny-write-execute as a prctl") Cc: stable@vger.kernel.org Signed-off-by: Florent Revest revest@chromium.org Suggested-by: Alexey Izbyshev izbyshev@ispras.ru Reviewed-by: David Hildenbrand david@redhat.com Reviewed-by: Kees Cook keescook@chromium.org Acked-by: Catalin Marinas catalin.marinas@arm.com
Why is this being offered to -stable? Does it fix any known problem?