Messages in this thread | | | Subject | Re: [PATCH v9 5/8] IMA: limit critical data measurement based on a label | From | Tushar Sugandhi <> | Date | Tue, 5 Jan 2021 12:28:19 -0800 |
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On 2020-12-24 6:29 a.m., Mimi Zohar wrote: > Hi Tushar, > > On Sat, 2020-12-12 at 10:02 -0800, Tushar Sugandhi wrote: >> System administrators should be able to limit which kernel subsystems >> they want to measure the critical data for. To enable that, an IMA policy >> condition to choose specific kernel subsystems is needed. This policy >> condition would constrain the measurement of the critical data based on >> a label for the given subsystems. > > Restricting which kernel integrity critical data is measured is not > only of interest to system administrators. Why single them out? > system administrators are usually responsible for system policies/configurations.They own modifications in the config files like ima-policy. That's why we wanted to address them to begin with. But you are correct. This is not only of interest to sysadmins. I will make the description more generic.
> Limiting which critical data is measured is based on a label, making it > flexible. In your use case scenario, you're grouping the label based > on kernel subsystem, but is that really necessary? In the broader > picture, there could be cross subsystem critical data being measured > based on a single label. > > Please think about the broader picture and re-write the patch > descirption more generically. > Makes sense. Will make the patch description more generic. >> >> Add a new IMA policy condition - "data_source:=" to the IMA func > > What is with "add"? You're "adding support for" or "defining" a new > policy condition. Remove the single hyphen, as explained in 3/8. > > Please replace "data_source" with something more generic (e.g. label). > Sounds good. Would you prefer "label" or something else like "data_label"?
In the policy file the "label" looks logical and more generic than "data_label". measure func=CRITICAL_DATA label=selinux
For the time being, I will stick with "label", please let me know if you prefer something else.
Thanks, Tushar
> thanks, > > Mimi > >> CRITICAL_DATA to allow measurement of various kernel subsystems. This >> policy condition would enable the system administrators to restrict the >> measurement to the labels listed in "data_source:=". >> >> Limit the measurement to the labels that are specified in the IMA >> policy - CRITICAL_DATA+"data_source:=". If "data_sources:=" is not >> provided with the func CRITICAL_DATA, the data from all the >> supported kernel subsystems is measured. >> >> Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com>
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