[PATCH] RDMA/uverbs: Fix CAP_NET_RAW check for flow create in user namespace

[Serge E. Hallyn]

On Mon, Mar 10, 2025 at 02:47:53PM +0000, Parav Pandit wrote:
> Hi,
> 
> > From: Serge E. Hallyn <serge at hallyn.com>
> > Sent: Monday, March 10, 2025 7:01 PM
> > 
> > On Sat, Mar 08, 2025 at 08:06:02PM +0200, Parav Pandit wrote:
> > > A process running in a non-init user namespace possesses the
> > > CAP_NET_RAW capability. However, the patch cited in the fixes tag
> > > checks the capability in the default init user namespace.
> > > Because of this, when the process was started by Podman in a
> > > non-default user namespace, the flow creation failed.
> > >
> > > Fix this issue by checking the CAP_NET_RAW networking capability in
> > > the owner user namespace that created the network namespace.
> > 
> > Hi,
> > 
> > you say
> > 
> >  > Fix this issue by checking the CAP_NET_RAW networking capability  > in the
> > owner user namespace that created the network namespace.
> > 
> > But in fact you are checking the CAP_NET_RAW against the user's network
> > namespace.  
> I didn't understand your comment.
> The fix takes the current process's network namespace by referring to current->nsproxy->net_ns.
> Each net ns has its owning user namespace who has created it.
> So the patch is checking caps in the such user namespace.
> 
> Can you please elaborate?

It looks like it got straightened out later with Eric's reply.  Please
let me know if that's not the case.

-serge