On Wed, 12 Dec 2018, Mickaël Salaün wrote:
Hi,
The goal of this patch series is to control script interpretation. A
new O_MAYEXEC flag used by sys_open() is added to enable userland script
interpreter to delegate to the kernel (and thus the system security
policy) the permission to interpret scripts or other files containing
what can be seen as commands.
The security policy is the responsibility of an LSM. A basic
system-wide policy is implemented with Yama and configurable through a
sysctl.
If you're depending on the script interpreter to flag that the user may
execute code, this seems to be equivalent in security terms to depending
on the user. e.g. what if the user uses ptrace and clears O_MAYEXEC?
--
James Morris
[off-list ref]