Messages in this thread | | | From | Matthew Garrett <> | Date | Thu, 2 Jan 2020 11:57:12 -0800 | Subject | Re: [PATCH] kconfig: Add kernel config option for fuzz testing. |
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On Tue, Dec 17, 2019 at 12:53 AM Dmitry Vyukov <dvyukov@google.com> wrote: > +Matthew for a lockdown question > We are considering [ab]using lockdown (you knew this will happen!) for > fuzzing kernel. LOCKDOWN_DEBUGFS is a no-go for us and we may want a > few other things that may be fuzzing-specific. > The current inflexibility comes from the global ordering of levels: > > if (kernel_locked_down >= level) > if (kernel_locked_down >= what) { > > Is it done for performance? Or for simplicity?
Simplicity. Based on discussion, we didn't want the lockdown LSM to enable arbitrary combinations of lockdown primitives, both because that would make it extremely difficult for userland developers and because it would make it extremely easy for local admins to accidentally configure policies that didn't achieve the desired outcome. There's no inherent problem in adding new options, but really right now they should fall into cases where they're protecting either the integrity of the kernel or preventing leakage of confidential information from the kernel.
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