Re: [PATCH] Documentation: Clarify f_cred vs current_cred() use

From: Jonathan Corbet
Date: Sun Jul 05 2020 - 16:05:05 EST


On Fri, 3 Jul 2020 10:44:22 -0700
Kees Cook <keescook@xxxxxxxxxxxx> wrote:

> When making access control choices from a file-based context, f_cred
> must be used instead of current_cred() to avoid confused deputy attacks
> where an open file may get passed to a more privileged process. Add a
> short paragraph to explicitly state the rationale.
>
> Cc: Jonathan Corbet <corbet@xxxxxxx>
> Cc: linux-doc@xxxxxxxxxxxxxxx
> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
> ---
> I forgot to include this patch in my kallsyms_show_value() f_cred series:
> https://lore.kernel.org/lkml/20200702232638.2946421-1-keescook@xxxxxxxxxxxx/
> I can either take this in that series, or it can go via docs?
> ---
> Documentation/security/credentials.rst | 4 ++++
> 1 file changed, 4 insertions(+)

I've applied it, thanks.

jon