Messages in this thread | | | Date | Mon, 24 Aug 2015 11:52:10 +0200 | Subject | Re: kdbus_proc_permission (Re: [GIT PULL] kdbus updates for Greg) | From | David Herrmann <> |
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Hi
On Mon, Aug 10, 2015 at 4:42 AM, Andy Lutomirski <luto@amacapital.net> wrote: > I spotted this: > > +/** > + * kdbus_proc_permission() - check /proc permissions on target pid > + * @pid_ns: namespace we operate in > + * @cred: credentials of requestor > + * @target: target process > + * > + * This checks whether a process with credentials @cred can access information > + * of @target in the namespace @pid_ns. This tries to follow /proc permissions, > + * but is slightly more restrictive. > + * > + * Return: The /proc access level (KDBUS_META_PROC_*) is returned. > + */ > +static unsigned int kdbus_proc_permission(const struct pid_namespace *pid_ns, > + const struct cred *cred, > + struct pid *target) > > That code ended up in a pull request, although AFAICT it was never in > any patch email sent to me or to any public mailing list. I suspect > it was at least partially a response to one of my old reviews.
Exactly. It's an attempt to model metadata access similar to /proc access (thus, access to kdbusfs implies access to procfs, but not vice versa (nor any implication on hidepid)).
> I haven't checked the context in which it's used, but in order for > kdbus_proc_permission to do what it claims to do, it appears to be > missing calls to security_inode_permission and > security_file_permission.
Both are expected to be added by lsm patches (both hooks you mentioned are empty if no lsm is selected).
Thanks David
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