Re: Why is /usr/include matched with /usr/inclu.e?

On Wed, Aug 21, 2019 at 09:57:14PM +0200, Nicolas Iooss wrote:
> Hi all,
> 
> While checking the patterns in refpolicy, I stumbled upon the
> following line in
> https://github.com/SELinuxProject/refpolicy/blob/RELEASE_2_20190609/policy/modules/kernel/files.fc#L200
> 
> /usr/inclu.e(/.*)? gen_context(system_u:object_r:usr_t,s0)

Probably to work around an m4-ism. There seems to be an m4 "include" built-in.

> 
> This pattern matches /usr/include and its content, but why is a dot
> used? Which other directories can it match?
> 
> The issue there is that a dot can match a slash, so the pattern also
> matches /usr/inclu/e/, which seems strange. This pattern has been
> introduced in the very early days of refpolicy's git repository,
> according to https://github.com/SELinuxProject/refpolicy/commit/f8ec0ad43b54437e2d9f0e48a773a64dbd9e543c#diff-e333cb52d2139f7a71f0dfbd32c06f70R117.
> Does anyone remember why the pattern for /usr/include is so special?
> 
> Thanks,
> Nicolas
> 

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Dominick Grift

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