Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1292260

Re: [PATCH 4.3] vrf: Fix memory leak on registration failure in vrf_newlink()

Show all headers | View raw

[Multipart message — attachments visible in raw view] - view raw

On Tue, 2015-12-15 at 08:15 -0700, David Ahern wrote:
> On 12/15/15 8:12 AM, Ben Hutchings wrote:
> > @@ -598,7 +599,10 @@ static int vrf_newlink(struct net *src_net, struct net_device *dev,
> > 
> >   	rcu_assign_pointer(dev->vrf_ptr, vrf_ptr);
> > 
> > -	return register_netdev(dev);
> > +	err = register_netdev(dev);
> > +	if (err)
> > +		kfree(vrf_ptr);
> > +	return err;
> >   }
> > 
> >   static size_t vrf_nl_getsize(const struct net_device *dev)
> > 
> 
> The rcu_assign_pointer should only be done if the register_netdev succeeded.

Oh, yes I see.  I though that no other task could access an
unregistered device, but register_netdev() can still fail after listing
the device.

Wait, it's worse, this is calling register_netdev() which will deadlock
as we already hold the RTNL lock.

Ben.

> Thanks for creating the patch.
> 
-- 
Ben Hutchings
Logic doesn't apply to the real world. - Marvin Minsky

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

Re: [PATCH 4.3] vrf: Fix memory leak on registration failure in  vrf_newlink() David Ahern <dsa@cumulusnetworks.com> - 2015-12-15 16:20 +0100
  Re: [PATCH 4.3] vrf: Fix memory leak on registration failure in  vrf_newlink() Ben Hutchings <ben@decadent.org.uk> - 2015-12-15 16:30 +0100
  [PATCH 4.3 2/2] vrf: fix double free and memory corruption on  register_netdevice failure Nikolay Aleksandrov <nikolay@cumulusnetworks.com> - 2015-12-15 16:40 +0100
    Re: [PATCH 4.3 2/2] vrf: fix double free and memory corruption on  register_netdevice failure David Ahern <dsa@cumulusnetworks.com> - 2015-12-15 17:00 +0100
    Re: [PATCH 4.3 2/2] vrf: fix double free and memory corruption on  register_netdevice failure Ben Hutchings <ben@decadent.org.uk> - 2015-12-15 18:10 +0100
  [PATCH 4.3 1/2] Revert "vrf: fix double free and memory corruption  on register_netdevice failure" Ben Hutchings <ben@decadent.org.uk> - 2015-12-15 16:40 +0100
    Re: [PATCH 4.3 1/2] Revert "vrf: fix double free and memory  corruption on register_netdevice failure" David Ahern <dsa@cumulusnetworks.com> - 2015-12-15 16:50 +0100

csiph-web