[PATCH v3 2/2] modules:capabilities: add a per-task modules autoload restriction
From: luto@kernel.org (Andy Lutomirski)
Date: 2017-05-05 16:19:14
Also in:
linux-api, lkml
On Thu, May 4, 2017 at 6:07 AM, Djalal Harouni [off-list ref] wrote:
On Sat, Apr 22, 2017 at 2:17 PM, Djalal Harouni [off-list ref] wrote:quoted
On Sat, Apr 22, 2017 at 1:28 AM, Andy Lutomirski [off-list ref] wrote:[...]quoted
quoted
My point is that all of these need some way to handle configuration and inheritance, and I don't think that a bunch of per-task prctls is the right way. As just an example, saying that interactive users can autoload modules but other users can't, or that certain systemd services can, etc, might be nice. Linus already complained that he (i.e. user "torvalds" or whatever) should be able to profile the kernel but that other uids should not be able to.Neat, maybe this could already be achieved with this interface and systemd-logind, "ModulesAutoloadUsers=andy" in logind.conf where "andy" is the only logged-in user able to trigger and autoload kernel modules. However maybe we should not restrict too much other bits or functionality of the other users, please let me will follow up later on it.quoted
I personally like my implicit_rights idea, and it might be interesting to prototype it.Andy following on the idea of per user settings, I'm curious did you manage to make some advance on how to store the user settings ? the user database format is old and not extensible, there was cgmanager or other libcgroup but for resources, and no simple thing for such restrictions example: "RestrictLinuxModules=user" that will prevent such users from making/loading extra Linux features/modules that are not already available...
I figured that user code would figure it out somehow. Text config file? There is another odd way it could be configured: just leave the inodes around in /dev/rights with appropriate permissions. Some startup script could re-instantiate them with the same permissions (via a syscall that does that atomically). -- To unsubscribe from this list: send the line "unsubscribe linux-security-module" in the body of a message to majordomo at vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html