On Fri, Apr 26, 2024 at 12:38:17PM -0700, Kees Cook wrote: > On Fri, Apr 26, 2024 at 07:22:49PM +0200, Mickaël Salaün wrote: > > According to the test environment, the mount point of the test's working > > directory may be shared or not, which changes the visibility of the > > nested "tmp" mount point for the test's parent process calling > > umount("tmp"). > > > > This was spotted while running tests on different Linux distributions, > > with different mount point configurations. > > Which distros did what? Actually it's not related to distros, but rather container runtime (Docker) vs. non-container environment. With Docker (at least on my environment) all mount points are private, which is not the case (by default) when running the same UML environment not in a container. See https://github.com/landlock-lsm/landlock-test-tools/pull/4 I'll update the description.