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make /boot and /lib/modules unreadable even for root
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Description

Similar to T937 but this is for defense in depth and even preventing root from getting access to kernel symbols.

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Impact
Normal

Event Timeline

Patrick triaged this task as Normal priority.Dec 7 2019, 8:13 AM
Patrick created this task.
Patrick renamed this task from make /boot unreadable even for root to make /boot and /lib/modules unreadable even for root.Dec 7 2019, 8:14 AM

/boot isn't allowed in init-systemd anyway so we don't need to add it to dangerous-files. Apparmor denies access to files that aren't explicitly allowed. The only reason we need to blacklist /lib/modules and not /boot is because we give access to all libraries.

Awesome!

Would an audit denyrule for /boot be useful for the sake of audit?

Any attempted access of /boot would be logged the same way anyway although it might be good to use that to stop it from showing up in aa-logprof.