[PATCH 3/5] audit: add netlink audit protocol bind to check capabilities on multicast join

[Richard Guy Briggs]

On 14/02/19, Eric Paris wrote:
> On Wed, 2014-02-19 at 13:08 -0500, Richard Guy Briggs wrote:
> > Register a netlink per-protocol bind fuction for audit to check userspace
> > process capabilities before allowing a multicast group connection.
> > 
> > Signed-off-by: Richard Guy Briggs <rgb at redhat.com>
> > ---
> >  kernel/audit.c |   10 ++++++++++
> >  1 files changed, 10 insertions(+), 0 deletions(-)
> > 
> > diff --git a/kernel/audit.c b/kernel/audit.c
> > index b5b2f72..f2d2d61 100644
> > --- a/kernel/audit.c
> > +++ b/kernel/audit.c
> > @@ -1050,10 +1050,20 @@ static void audit_receive(struct sk_buff  *skb)
> >  	mutex_unlock(&audit_cmd_mutex);
> >  }
> >  
> > +/* Run custom bind function on netlink socket group connect or bind requests. */
> > +static int audit_bind(int group)
> > +{
> > +	if (!capable(CAP_AUDIT_READ))
> 
> Not a great idea to use CAP_AUDIT_READ before you define it in patch4

<blush>

> > +		return -EPERM;
> > +
> > +	return 0;
> > +}
> > +
> >  static int __net_init audit_net_init(struct net *net)
> >  {
> >  	struct netlink_kernel_cfg cfg = {
> >  		.input	= audit_receive,
> > +		.bind	= audit_bind,
> >  	};
> >  
> >  	struct audit_net *aunet = net_generic(net, audit_net_id);

- RGB

--
Richard Guy Briggs <rbriggs at redhat.com>
Senior Software Engineer, Kernel Security, AMER ENG Base Operating Systems, Red Hat
Remote, Ottawa, Canada
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