Re: [PATCH 3/6] io_uring: add support for IORING_OP_OPENAT

Stefan Metzmacher
2020-01-08T13:25:26Z

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Hi Jens,

> This works just like openat(2), except it can be performed async. For
> the normal case of a non-blocking path lookup this will complete
> inline. If we have to do IO to perform the open, it'll be done from
> async context.

Did you already thought about the credentials being used for the async
open? The application could call setuid() and similar calls to change
the credentials of the userspace process/threads. In order for
applications like samba to use this async openat, it would be required
to specify the credentials for each open, as we have to multiplex
requests from multiple user sessions in one process.

This applies to non-fd based syscall. Also for an async connect
to a unix domain socket.

Do you have comments on this?

Thanks!
metze

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