Messages in this thread | | | Subject | Re: [RFC] /dev/ioasid uAPI proposal | From | "Enrico Weigelt, metux IT consult" <> | Date | Wed, 9 Jun 2021 10:51:49 +0200 |
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On 08.06.21 21:00, Jason Gunthorpe wrote:
> Eg I can do open() on a file and I get to keep that FD. I get to keep > that FD even if someone later does chmod() on that file so I can't > open it again. > > There are lots of examples where a one time access control check > provides continuing access to a resource. I feel the ongoing proof is > the rarity in Unix.. 'revoke' is an uncommon concept in Unix..
Yes, it's even possible that somebody w/ privileges opens an fd and hands it over to somebody unprivileged (eg. via unix socket). This is a very basic unix concept. If some (already opened) fd now suddenly behaves differently based on the current caller, that would be a break with traditional unix semantics.
--mtx
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