lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Thu, 17 Feb 2022 16:24:18 -0500 From: Mimi Zohar <zohar@...ux.ibm.com> To: Stefan Berger <stefanb@...ux.ibm.com>, linux-integrity@...r.kernel.org Cc: serge@...lyn.com, christian.brauner@...ntu.com, containers@...ts.linux.dev, dmitry.kasatkin@...il.com, ebiederm@...ssion.com, krzysztof.struczynski@...wei.com, roberto.sassu@...wei.com, mpeters@...hat.com, lhinds@...hat.com, lsturman@...hat.com, puiterwi@...hat.com, jejb@...ux.ibm.com, jamjoom@...ibm.com, linux-kernel@...r.kernel.org, paul@...l-moore.com, rgb@...hat.com, linux-security-module@...r.kernel.org, jmorris@...ei.org Subject: Re: [PATCH v10 11/27] ima: Move ima_lsm_policy_notifier into ima_namespace On Thu, 2022-02-17 at 15:59 -0500, Stefan Berger wrote: > > > >> Move the ima_lsm_policy_notifier into the ima_namespace. Each IMA > >> namespace can now register its own LSM policy change notifier callback. > >> The policy change notifier for the init_ima_ns still remains in init_ima() > >> and therefore handle the registration of the callback for all other > >> namespaces in init_ima_namespace(). > >> > >> Suppress the kernel warning 'rule for LSM <label> is undefined` for all > >> other IMA namespaces than the init_ima_ns. > > Instead of ignoring the warnings totally, perhaps use either the > > "ratelimited" or "once" function options for non init_ima_ns. It would > > be nice if these functions could be namespace aware, so that each > > affected IMA namespace would contain at least one warning. > > The problem is that any user can now repeatedly create user namespaces > and with that IMA namespaces and cause the kernel log to fill up with > these messages and also flood the audit log -- I guess one could > describe it as an unwanted side-effect. I am afraid that for as long as > the kernel log is not namespaced it's probably best to just turn them > off for non-init_ima_ns. There are functions - pr_warn_once() or pr_warn_ratelimited() - that limit the number of kernel messages. In addition to the number of potential kernel messages, there's also the issue of being able to differentiate between init_ima_ns and other IMA namespaces. I think that is more of a concern than rate limiting. -- thanks, Mimi
Powered by blists - more mailing lists