On Mon, Jul 8, 2024 at 10:33 AM Florian Weimer [off-list ref] wrote:

* Jeff Xu:

quoted

On Mon, Jul 8, 2024 at 9:26 AM Florian Weimer [off-list ref] wrote:

quoted

* Jeff Xu:

quoted

Will dynamic linkers use the execveat(AT_CHECK) to check shared
libraries too ?  or just the main executable itself.

I expect that dynamic linkers will have to do this for everything they
map.

Then all the objects (.so, .sh, etc.) will go through  the check from
execveat's main  to security_bprm_creds_for_exec(), some of them might
be specific for the main executable ?

If we want to avoid that, we could have an agreed-upon error code which
the LSM can signal that it'll never fail AT_CHECK checks, so we only
have to perform the extra system call once.

Right, something like that.
I would prefer not having AT_CHECK specific code in LSM code as an
initial goal, if that works, great.

-Jeff

Thanks,
Florian