Re: [PATCH v22 04/12] landlock: Add ptrace restrictions

Jann Horn
2020-10-29T01:07:11Z

On Tue, Oct 27, 2020 at 9:04 PM Mickaël Salaün <mic@digikod.net> wrote:
> Using ptrace(2) and related debug features on a target process can lead
> to a privilege escalation. Indeed, ptrace(2) can be used by an attacker
> to impersonate another task and to remain undetected while performing
> malicious activities. Thanks to ptrace_may_access(), various part of
> the kernel can check if a tracer is more privileged than a tracee.
>
> A landlocked process has fewer privileges than a non-landlocked process
> and must then be subject to additional restrictions when manipulating
> processes. To be allowed to use ptrace(2) and related syscalls on a
> target process, a landlocked process must have a subset of the target
> process's rules (i.e. the tracee must be in a sub-domain of the tracer).
>
> Cc: James Morris <jmorris@namei.org>
> Cc: Jann Horn <jannh@google.com>
> Cc: Kees Cook <keescook@chromium.org>
> Cc: Serge E. Hallyn <serge@hallyn.com>
> Signed-off-by: Mickaël Salaün <mic@linux.microsoft.com>

Reviewed-by: Jann Horn <jannh@google.com>