Re: [rfc] fcntl: Add F_GETOWNER_UIDS option

From: Kees Cook
Date: Fri Mar 30 2012 - 15:46:52 EST

On Fri, Mar 30, 2012 at 9:15 AM, Serge E. Hallyn <serge@xxxxxxxxxx> wrote:
> Quoting Cyrill Gorcunov (gorcunov@xxxxxxxxxx):
>> On Fri, Mar 30, 2012 at 09:12:19AM -0500, Serge Hallyn wrote:
>> ...
>> > >
>> > > Yes, I wanna take a look on Eric's set first just to get right
>> > > "picture" of everything. And I wanted to find a minimal solution
>> > > with current kernel code base which could be extended in future.
>> > >
>> > > That said I guess the current init-ns-only approach should do the
>> > > trick for a while. And (thanks for pointing) I need to add a test
>> > > if a caller which tries to obtain uids has enought credentials
>> > > for that (probably CAP_FOWNER), right?
>> >
>> > Sorry, I'm not sure which caller you mean.  Neither f_setown nor
>> > f_getown require privilege right now.  Oh, you mean at restart?
>> I meant the dumper. Yes, at moment f_get/setown requires no privileges
>> but I'm not sure if uid/euid is same or less sensible information
>> than pid, that's why I though CAP_FOWNER might be worth to add, no?
> Hmm, I would say no, but that might be a good question for kees.
> IMO it's not sensitive information and so no sense requiring privilege
> (and encouraging handing out of extra privilage to get at the info)

Nothing jumps out at me about just seeing uid/euid. Everything can be
construed as an information leak, but this don't seem like something
that needs special protection.


Kees Cook
ChromeOS Security
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at