Re: [PATCH v2] ima: instantiate the bprm_creds_for_exec() hook

Stefan Berger
2024-12-04T19:01:21Z

On 12/3/24 6:34 PM, Mimi Zohar wrote:
> Like direct file execution (e.g. ./script.sh), indirect file exection

typo: execution

> (e.g. sh script.sh) needs to be measured and appraised. Instantiate

If I understand the underlying patches correctly then 'sh script.sh'
would be evaluated with execveat(AT_CHECK) but this requires the execute
flag to be set. To maintain backwards compatibility sh cannot assume
that script.sh has the execute flag set since it doesn't need today:

$ echo 'echo hi' > foo.sh
$ sh foo.sh
hi

the same is true for python:

$ echo 'print("hi")' > foo.py
$ python foo.py
hi

I am not sure which interpreters are going to be able to take advantage
of this or whether they will behave differently if the x bit is set
versus when it is not set...?