On Tue, Jul 09, 2024 at 11:57:27AM -0700, Jeff Xu wrote:

On Tue, Jul 9, 2024 at 2:18 AM Mickaël Salaün [off-list ref] wrote:

quoted

On Mon, Jul 08, 2024 at 10:52:36AM -0700, Jeff Xu wrote:

quoted

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

quoted

* 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 ?

Yes, we should check every executable code (including seccomp filters)
to get a consistent policy.

What do you mean by "specific for the main executable"?

I meant:

The check is for the exe itself, not .so, etc.

For example:  /usr/bin/touch is checked.
not the shared objects:
ldd /usr/bin/touch
linux-vdso.so.1 (0x00007ffdc988f000)
libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f59b6757000)
/lib64/ld-linux-x86-64.so.2 (0x00007f59b6986000)

ld.so should be patched to check shared-objects.

Basically, I asked if the check can be extended to shared-objects,
seccomp filters, etc, without modifying existing LSMs.

Yes, the check should be used against any piece of code such as
shared-objects, seccomp filters...

you pointed out "LSM should not need to be updated with this patch
series.", which already answered my question.

Thanks.
-Jeff

-Jeff