Messages in this thread | | | Date | Wed, 23 Feb 2022 15:45:26 -0500 | Subject | Re: [PATCH v10 26/27] ima: Limit number of policy rules in non-init_ima_ns | From | Stefan Berger <> |
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On 2/23/22 12:04, Mimi Zohar wrote: > On Wed, 2022-02-23 at 11:37 -0500, Stefan Berger wrote: >> On 2/23/22 10:38, Mimi Zohar wrote: >>> On Tue, 2022-02-01 at 15:37 -0500, Stefan Berger wrote: >>>> Limit the number of policy rules one can set in non-init_ima_ns to a >>>> hardcoded 1024 rules. If the user attempts to exceed this limit by >>>> setting too many additional rules, emit an audit message with the cause >>>> 'too-many-rules' and simply ignore the newly added rules. >>> This paragraph describes 'what' you're doing, not 'why'. Please prefix >>> this paragraph with a short, probably one sentence, reason for the >>> change. >>>> Switch the accounting for the memory allocated for IMA policy rules to >>>> GFP_KERNEL_ACCOUNT so that cgroups kernel memory accounting takes effect. >>> Does this change affect the existing IMA policy rules for init_ima_ns? >> There's typically no cgroup for the int_ima_ns, so not effect on >> init_ima_ns. >> >> Here's the updated text: >> >> Limit the number of policy rules one can set in non-init_ima_ns to a >> hardcoded 1024 rules to restrict the amount of memory used for IMA's >> policy. > The question is "why" there should be a difference between the > init_ima_ns and non-init_ima_ns cases. Perhaps something like, "Only
Chistian had suggested it to not have the number of policy rules unbounded.
> host root with CAP_SYS_ADMIN may write init_ima_ns policy rules, but in > the non-init_ima_ns case root in the namespace with CAP_MAC_ADMIN > privileges may write IMA policy rules. Limit the total number of IMA > policy rules per namespace."
What does it have to do with CAP_SYS_ADMIN and CAP_MAC_ADMIN and why mention these here? It seem primarily a limit of number of rules to avoid huge kernel memory consumption in the case that a cgroup limit for memory was not set up.
> >> Ignore the added rules if the user attempts to exceed this >> limit by setting too many additional rules. >> >> Switch the accounting for the memory allocated for IMA policy rules to >> GFP_KERNEL_ACCOUNT so that cgroups kernel memory accounting takes effect. >> This switch has no effect on the init_ima_ns. > thanks, > > Mimi >
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