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SubjectRe: [PATCH v10 05/11] seccomp: add system call filtering using BPF
On Wed, 2012-02-22 at 09:19 +0100, Indan Zupancic wrote:
> Alternative approach: Tell the arch at filter install time and only run the
> filters with the same arch as the current system call. If no filters are run,
> deny the systemcall.
> Advantages:
> - Filters don't have to check the arch every syscall entry.
> - Secure by default. Filters don't have to do anything arch specific to
> be secure, no surprises possible.
> - If a new arch comes into existence, there is no chance of old filters
> becoming buggy and insecure. This is especially true for archs that
> had only one mode, but added another one later on: Old filters had no
> need to check the mode at all.

What about when there are multiple layers of restrictions? So long as
any one layer covers the new architecture, there is no default-deny even
though the other layers might not cover it.

I would have thought the way to make sure the architecture is always
checked is to pack it together with the syscall number.


Ben Hutchings, Staff Engineer, Solarflare
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.

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