On Tue, Oct 2, 2018 at 11:57 AM, John Johansen <john.johansen@xxxxxxxxxxxxx> wrote: > Under the current scheme > > lsm.enabled=selinux > > could actually mean selinux,yama,loadpin,something_else are > enabled. If we extend this behavior to when full stacking lands > > lsm.enabled=selinux,yama > > might mean selinux,yama,apparmor,loadpin,something_else > > and what that list is will vary from kernel to kernel, which I think > is harder for the user than the lsm.enabled list being what is > actually enabled at boot Ah, I think I missed this in your earlier emails. What you don't like here is that "lsm.enable=" is additive. You want it to be explicit. Are you okay with lsm.order= having fallback? The situation we were trying to solve was with new LSMs getting implicitly disabled if someone is booting with an explicit list. For example: lsm.enable=yama,apparmor means when "landlock" gets added to the kernel, it will be implicitly disabled. > If we have to have multiple kernel parameter, I prefer a behvior where > if you hav conflicting kernel parameters specified > > apparmor=0 lsm.enabled=apparmor > > that the conflict is logged and the lsm is left disabled, as I think > it is easier for users to understand than the overrides scheme of v3, > and sans logging of the conflict is effectively what we had in the > past > > apparmor=0 security=apparmor > or > apparmor=1 security=selinux > > would result in apparmor being disabed Okay, so for this part you want per-LSM boot param to have priority (which seems to match SELinux's concerns), possibly logging the conflict, but still accepting the apparmor= and selinux= state. security= would still driving initialization ordering (so I think the behavior I have in the series would be correct). > That being said I get we have a mess currently, and there really > doesn't seem to be a good way to fix it. I think getting this right > for the user is important enough that I am willing to break current > apparmor userspace api. While apparmor=0 is documented we have also > documented security=X for years and apparmor=0 isn't used too often > so I think we can drop it to help clean this mess up abit. > > I am not going to Nak, or block on v3 behavior if that is considered > the best path forward after this discussion/rant. I could define CONFIG_LSM_ENABLE as being "additive" to SECURITY_APPARMOR_BOOTPARAM_VALUE and SECURITY_SELINUX_BOOTPARAM_VALUE? -Kees -- Kees Cook Pixel Security
