* [PATCH net-next] macvlan: fix failure during registration v3
@ 2016-04-23 22:03 Francesco Ruggeri
2016-04-25 19:00 ` Eric W. Biederman
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Francesco Ruggeri @ 2016-04-23 22:03 UTC (permalink / raw)
To: netdev
Cc: Francesco Ruggeri, Eric W. Biederman, David S. Miller, Mahesh Bandewar
If macvlan_common_newlink fails in register_netdevice after macvlan_init
then it decrements port->count twice, first in macvlan_uninit (from
register_netdevice or rollback_registered) and then again in
macvlan_common_newlink.
A similar problem may exist in the ipvlan driver.
This patch consolidates modifications to port->count into macvlan_init
and macvlan_uninit (thanks to Eric Biederman for suggesting this approach).
v3: remove macvtap specific bits.
Signed-off-by: Francesco Ruggeri <fruggeri@arista.com>
---
drivers/net/macvlan.c | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)
diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index 2bcf1f3..cb01023 100644
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -795,6 +795,7 @@ static int macvlan_init(struct net_device *dev)
{
struct macvlan_dev *vlan = netdev_priv(dev);
const struct net_device *lowerdev = vlan->lowerdev;
+ struct macvlan_port *port = vlan->port;
dev->state = (dev->state & ~MACVLAN_STATE_MASK) |
(lowerdev->state & MACVLAN_STATE_MASK);
@@ -812,6 +813,8 @@ static int macvlan_init(struct net_device *dev)
if (!vlan->pcpu_stats)
return -ENOMEM;
+ port->count += 1;
+
return 0;
}
@@ -1312,10 +1315,9 @@ int macvlan_common_newlink(struct net *src_net, struct net_device *dev,
return err;
}
- port->count += 1;
err = register_netdevice(dev);
if (err < 0)
- goto destroy_port;
+ return err;
dev->priv_flags |= IFF_MACVLAN;
err = netdev_upper_dev_link(lowerdev, dev);
@@ -1330,10 +1332,6 @@ int macvlan_common_newlink(struct net *src_net, struct net_device *dev,
unregister_netdev:
unregister_netdevice(dev);
-destroy_port:
- port->count -= 1;
- if (!port->count)
- macvlan_port_destroy(lowerdev);
return err;
}
--
1.8.1.4
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH net-next] macvlan: fix failure during registration v3
2016-04-23 22:03 [PATCH net-next] macvlan: fix failure during registration v3 Francesco Ruggeri
@ 2016-04-25 19:00 ` Eric W. Biederman
2016-04-26 18:54 ` Mahesh Bandewar
2016-04-26 19:19 ` David Miller
2 siblings, 0 replies; 6+ messages in thread
From: Eric W. Biederman @ 2016-04-25 19:00 UTC (permalink / raw)
To: Francesco Ruggeri; +Cc: netdev, David S. Miller, Mahesh Bandewar
Francesco Ruggeri <fruggeri@arista.com> writes:
> If macvlan_common_newlink fails in register_netdevice after macvlan_init
> then it decrements port->count twice, first in macvlan_uninit (from
> register_netdevice or rollback_registered) and then again in
> macvlan_common_newlink.
> A similar problem may exist in the ipvlan driver.
> This patch consolidates modifications to port->count into macvlan_init
> and macvlan_uninit (thanks to Eric Biederman for suggesting this approach).
>
> v3: remove macvtap specific bits.
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
> Signed-off-by: Francesco Ruggeri <fruggeri@arista.com>
> ---
> drivers/net/macvlan.c | 10 ++++------
> 1 file changed, 4 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
> index 2bcf1f3..cb01023 100644
> --- a/drivers/net/macvlan.c
> +++ b/drivers/net/macvlan.c
> @@ -795,6 +795,7 @@ static int macvlan_init(struct net_device *dev)
> {
> struct macvlan_dev *vlan = netdev_priv(dev);
> const struct net_device *lowerdev = vlan->lowerdev;
> + struct macvlan_port *port = vlan->port;
>
> dev->state = (dev->state & ~MACVLAN_STATE_MASK) |
> (lowerdev->state & MACVLAN_STATE_MASK);
> @@ -812,6 +813,8 @@ static int macvlan_init(struct net_device *dev)
> if (!vlan->pcpu_stats)
> return -ENOMEM;
>
> + port->count += 1;
> +
> return 0;
> }
>
> @@ -1312,10 +1315,9 @@ int macvlan_common_newlink(struct net *src_net, struct net_device *dev,
> return err;
> }
>
> - port->count += 1;
> err = register_netdevice(dev);
> if (err < 0)
> - goto destroy_port;
> + return err;
>
> dev->priv_flags |= IFF_MACVLAN;
> err = netdev_upper_dev_link(lowerdev, dev);
> @@ -1330,10 +1332,6 @@ int macvlan_common_newlink(struct net *src_net, struct net_device *dev,
>
> unregister_netdev:
> unregister_netdevice(dev);
> -destroy_port:
> - port->count -= 1;
> - if (!port->count)
> - macvlan_port_destroy(lowerdev);
>
> return err;
> }
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH net-next] macvlan: fix failure during registration v3
2016-04-23 22:03 [PATCH net-next] macvlan: fix failure during registration v3 Francesco Ruggeri
2016-04-25 19:00 ` Eric W. Biederman
@ 2016-04-26 18:54 ` Mahesh Bandewar
2016-04-26 19:07 ` Francesco Ruggeri
2016-04-26 19:19 ` David Miller
2 siblings, 1 reply; 6+ messages in thread
From: Mahesh Bandewar @ 2016-04-26 18:54 UTC (permalink / raw)
To: Francesco Ruggeri; +Cc: linux-netdev, Eric W. Biederman, David S. Miller
On Sat, Apr 23, 2016 at 3:03 PM, Francesco Ruggeri <fruggeri@arista.com> wrote:
> If macvlan_common_newlink fails in register_netdevice after macvlan_init
> then it decrements port->count twice, first in macvlan_uninit (from
> register_netdevice or rollback_registered) and then again in
> macvlan_common_newlink.
> A similar problem may exist in the ipvlan driver.
That is correct! The problem exists in ipvlan driver also. I'll cook a
patch to fix this in ipvlan driver.
> This patch consolidates modifications to port->count into macvlan_init
> and macvlan_uninit (thanks to Eric Biederman for suggesting this approach).
>
> v3: remove macvtap specific bits.
>
> Signed-off-by: Francesco Ruggeri <fruggeri@arista.com>
> ---
> drivers/net/macvlan.c | 10 ++++------
> 1 file changed, 4 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
> index 2bcf1f3..cb01023 100644
> --- a/drivers/net/macvlan.c
> +++ b/drivers/net/macvlan.c
> @@ -795,6 +795,7 @@ static int macvlan_init(struct net_device *dev)
> {
> struct macvlan_dev *vlan = netdev_priv(dev);
> const struct net_device *lowerdev = vlan->lowerdev;
> + struct macvlan_port *port = vlan->port;
>
> dev->state = (dev->state & ~MACVLAN_STATE_MASK) |
> (lowerdev->state & MACVLAN_STATE_MASK);
> @@ -812,6 +813,8 @@ static int macvlan_init(struct net_device *dev)
> if (!vlan->pcpu_stats)
> return -ENOMEM;
>
> + port->count += 1;
> +
> return 0;
> }
>
> @@ -1312,10 +1315,9 @@ int macvlan_common_newlink(struct net *src_net, struct net_device *dev,
> return err;
> }
>
> - port->count += 1;
> err = register_netdevice(dev);
> if (err < 0)
> - goto destroy_port;
> + return err;
>
> dev->priv_flags |= IFF_MACVLAN;
> err = netdev_upper_dev_link(lowerdev, dev);
> @@ -1330,10 +1332,6 @@ int macvlan_common_newlink(struct net *src_net, struct net_device *dev,
>
> unregister_netdev:
> unregister_netdevice(dev);
> -destroy_port:
> - port->count -= 1;
> - if (!port->count)
> - macvlan_port_destroy(lowerdev);
I think you still need this when it fails netdev_upper_dev_link(). The
only thing you should remove is the label.
>
> return err;
> }
> --
> 1.8.1.4
>
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH net-next] macvlan: fix failure during registration v3
2016-04-26 18:54 ` Mahesh Bandewar
@ 2016-04-26 19:07 ` Francesco Ruggeri
2016-04-26 21:36 ` Mahesh Bandewar
0 siblings, 1 reply; 6+ messages in thread
From: Francesco Ruggeri @ 2016-04-26 19:07 UTC (permalink / raw)
To: Mahesh Bandewar; +Cc: linux-netdev, Eric W. Biederman, David S. Miller
On Tue, Apr 26, 2016 at 11:54 AM, Mahesh Bandewar <maheshb@google.com> wrote:
>
> On Sat, Apr 23, 2016 at 3:03 PM, Francesco Ruggeri <fruggeri@arista.com> wrote:
> > If macvlan_common_newlink fails in register_netdevice after macvlan_init
> > then it decrements port->count twice, first in macvlan_uninit (from
> > register_netdevice or rollback_registered) and then again in
> > macvlan_common_newlink.
> > A similar problem may exist in the ipvlan driver.
> That is correct! The problem exists in ipvlan driver also. I'll cook a
> patch to fix this in ipvlan driver.
>
> > This patch consolidates modifications to port->count into macvlan_init
> > and macvlan_uninit (thanks to Eric Biederman for suggesting this approach).
> >
> > v3: remove macvtap specific bits.
> >
> > Signed-off-by: Francesco Ruggeri <fruggeri@arista.com>
> > ---
> > drivers/net/macvlan.c | 10 ++++------
> > 1 file changed, 4 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
> > index 2bcf1f3..cb01023 100644
> > --- a/drivers/net/macvlan.c
> > +++ b/drivers/net/macvlan.c
> > @@ -795,6 +795,7 @@ static int macvlan_init(struct net_device *dev)
> > {
> > struct macvlan_dev *vlan = netdev_priv(dev);
> > const struct net_device *lowerdev = vlan->lowerdev;
> > + struct macvlan_port *port = vlan->port;
> >
> > dev->state = (dev->state & ~MACVLAN_STATE_MASK) |
> > (lowerdev->state & MACVLAN_STATE_MASK);
> > @@ -812,6 +813,8 @@ static int macvlan_init(struct net_device *dev)
> > if (!vlan->pcpu_stats)
> > return -ENOMEM;
> >
> > + port->count += 1;
> > +
> > return 0;
> > }
> >
> > @@ -1312,10 +1315,9 @@ int macvlan_common_newlink(struct net *src_net, struct net_device *dev,
> > return err;
> > }
> >
> > - port->count += 1;
> > err = register_netdevice(dev);
> > if (err < 0)
> > - goto destroy_port;
> > + return err;
> >
> > dev->priv_flags |= IFF_MACVLAN;
> > err = netdev_upper_dev_link(lowerdev, dev);
> > @@ -1330,10 +1332,6 @@ int macvlan_common_newlink(struct net *src_net, struct net_device *dev,
> >
> > unregister_netdev:
> > unregister_netdevice(dev);
> > -destroy_port:
> > - port->count -= 1;
> > - if (!port->count)
> > - macvlan_port_destroy(lowerdev);
> I think you still need this when it fails netdev_upper_dev_link(). The
> only thing you should remove is the label.
I don't think so. I think the double decrement also occurred in this case.
unregister_netdevice invokes rollback_registered/macvlan_uninit
which does the decrement.
Thanks,
Francesco
> >
> > return err;
> > }
> > --
> > 1.8.1.4
> >
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH net-next] macvlan: fix failure during registration v3
2016-04-26 19:07 ` Francesco Ruggeri
@ 2016-04-26 21:36 ` Mahesh Bandewar
0 siblings, 0 replies; 6+ messages in thread
From: Mahesh Bandewar @ 2016-04-26 21:36 UTC (permalink / raw)
To: Francesco Ruggeri; +Cc: linux-netdev, Eric W. Biederman, David S. Miller
[...]
>> > -destroy_port:
>> > - port->count -= 1;
>> > - if (!port->count)
>> > - macvlan_port_destroy(lowerdev);
>> I think you still need this when it fails netdev_upper_dev_link(). The
>> only thing you should remove is the label.
>
> I don't think so. I think the double decrement also occurred in this case.
> unregister_netdevice invokes rollback_registered/macvlan_uninit
> which does the decrement.
>
I thought macvlan_port_destroy() does not get called but it is called
from macvlan_uninit(). So it's all good. Thanks.
> Thanks,
> Francesco
>
>> >
>> > return err;
>> > }
>> > --
>> > 1.8.1.4
>> >
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH net-next] macvlan: fix failure during registration v3
2016-04-23 22:03 [PATCH net-next] macvlan: fix failure during registration v3 Francesco Ruggeri
2016-04-25 19:00 ` Eric W. Biederman
2016-04-26 18:54 ` Mahesh Bandewar
@ 2016-04-26 19:19 ` David Miller
2 siblings, 0 replies; 6+ messages in thread
From: David Miller @ 2016-04-26 19:19 UTC (permalink / raw)
To: fruggeri; +Cc: netdev, ebiederm, maheshb
From: Francesco Ruggeri <fruggeri@arista.com>
Date: Sat, 23 Apr 2016 15:03:32 -0700
> If macvlan_common_newlink fails in register_netdevice after macvlan_init
> then it decrements port->count twice, first in macvlan_uninit (from
> register_netdevice or rollback_registered) and then again in
> macvlan_common_newlink.
> A similar problem may exist in the ipvlan driver.
> This patch consolidates modifications to port->count into macvlan_init
> and macvlan_uninit (thanks to Eric Biederman for suggesting this approach).
>
> v3: remove macvtap specific bits.
>
> Signed-off-by: Francesco Ruggeri <fruggeri@arista.com>
Applied.
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2016-04-26 21:36 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2016-04-23 22:03 [PATCH net-next] macvlan: fix failure during registration v3 Francesco Ruggeri
2016-04-25 19:00 ` Eric W. Biederman
2016-04-26 18:54 ` Mahesh Bandewar
2016-04-26 19:07 ` Francesco Ruggeri
2016-04-26 21:36 ` Mahesh Bandewar
2016-04-26 19:19 ` David Miller
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