[PATCH net] macvlan: fix allmulti reference counting in passthru mode

[PATCH net] macvlan: fix allmulti reference counting in passthru mode

[Prasad Koya]

Enabling allmulticast on a down passthru macvlan, bringing it up,
then toggling allmulticast off and on can underflow the lower device's
allmulti reference count.

macvlan_change_rx_flags() only propagates IFF_ALLMULTI changes while
the macvlan is up. However, the passthru path in macvlan_open() skips
taking an allmulti reference when IFF_ALLMULTI is already set.
Clearing allmulticast after opening the device therefore decrements
a reference that was never taken. With no other allmulti users, the
unsigned counter wraps from zero to UINT_MAX. The next increment
fails with -EOVERFLOW and reports "allmulti touches roof".

Signed-off-by: Prasad Koya <prasad@arista.com>
---
Reproducer:

  #!/bin/bash
  set -euo pipefail

  ns=allmulti-test
  host=am-veth0
  peer=am-veth1
  mv=am-mv0

  cleanup()
  {
      ip netns del "$ns" 2>/dev/null || true
  }
  trap cleanup EXIT

  ip netns add "$ns"
  ip link add "$host" type veth peer name "$peer"
  ip link set "$peer" netns "$ns"

  ip link set "$host" up
  ip -n "$ns" link set lo up
  ip -n "$ns" link set "$peer" up

  ip -n "$ns" link add link "$peer" name "$mv" type macvlan mode passthru

  ip -n "$ns" link set dev "$mv" allmulticast on
  ip -n "$ns" link set dev "$mv" up
  ip -n "$ns" link set dev "$mv" allmulticast off
  ip -n "$ns" link set dev "$mv" allmulticast on

 drivers/net/macvlan.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index afad90b9222a..e20d587453d1 100644
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -643,6 +643,14 @@ static int macvlan_open(struct net_device *dev)
 			if (err < 0)
 				goto out;
 		}
+		if (dev->flags & IFF_ALLMULTI) {
+			err = dev_set_allmulti(lowerdev, 1);
+			if (err < 0) {
+				if (!(vlan->flags & MACVLAN_FLAG_NOPROMISC))
+					dev_set_promiscuity(lowerdev, -1);
+				goto out;
+			}
+		}
 		goto hash_add;
 	}
 
@@ -713,6 +721,8 @@ static int macvlan_stop(struct net_device *dev)
 	dev_mc_unsync(lowerdev, dev);
 
 	if (macvlan_passthru(vlan->port)) {
+		if (dev->flags & IFF_ALLMULTI)
+			dev_set_allmulti(lowerdev, -1);
 		if (!(vlan->flags & MACVLAN_FLAG_NOPROMISC))
 			dev_set_promiscuity(lowerdev, -1);
 		goto hash_del;

base-commit: 7076f684d5132e6a6145e1da2fa74771ecd052e5
-- 
2.43.0

Re: [PATCH net] macvlan: fix allmulti reference counting in passthru mode

[netdev-bot+sinfo]

Hi!

This is an automated message. This series looks like a fix, but its
commit messages seem to be missing some information:

 - How the issue was discovered, e.g. hit in production, hit during
   development, syzbot report, manual code inspection, LLM or static
   analysis tool scan.

Please do not repost the series just to address the above. Instead,
reply to this email with the missing information, so that reviewers
can take it into account. If the series needs another revision for
other reasons, please include the information in the commit messages
then.

The evaluation is done by an LLM so it may be wrong, if you think
that is the case please reply and explain.

Re: [PATCH net] macvlan: fix allmulti reference counting in passthru mode

[Prasad Koya]

The issue was observed during development testing with 5.10 and 6.12
kernels. It was reproduced on Linux 6.12.68 by enabling allmulticast
on a down passthru macvlan, bringing it up, and toggling allmulticast
off and on. This triggered the “allmulti touches roof” warning.

> On Mon, Oct 26, 2026 at 7:51 PM <netdev-bot+sinfo@kernel.org> wrote:
>>
>> Hi!
>>
>> This is an automated message. This series looks like a fix, but its
>> commit messages seem to be missing some information:
>>
>>  - How the issue was discovered, e.g. hit in production, hit during
>>    development, syzbot report, manual code inspection, LLM or static
>>    analysis tool scan.
>>
>> Please do not repost the series just to address the above. Instead,
>> reply to this email with the missing information, so that reviewers
>> can take it into account. If the series needs another revision for
>> other reasons, please include the information in the commit messages
>> then.
>>
>> The evaluation is done by an LLM so it may be wrong, if you think
>> that is the case please reply and explain.

Re: [PATCH net] macvlan: fix allmulti reference counting in passthru mode

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net.git (main)
by Dave Miller <davem@davem-thinkpadp1gen8.ibmlond.csb>:

On Mon, 26 Oct 2026 19:46:35 -0700 you wrote:
> Enabling allmulticast on a down passthru macvlan, bringing it up,
> then toggling allmulticast off and on can underflow the lower device's
> allmulti reference count.
> 
> macvlan_change_rx_flags() only propagates IFF_ALLMULTI changes while
> the macvlan is up. However, the passthru path in macvlan_open() skips
> taking an allmulti reference when IFF_ALLMULTI is already set.
> Clearing allmulticast after opening the device therefore decrements
> a reference that was never taken. With no other allmulti users, the
> unsigned counter wraps from zero to UINT_MAX. The next increment
> fails with -EOVERFLOW and reports "allmulti touches roof".
> 
> [...]

Here is the summary with links:
  - [net] macvlan: fix allmulti reference counting in passthru mode
    https://git.kernel.org/netdev/net/c/d8a4f4c59da5

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html

Re: [PATCH net] macvlan: fix allmulti reference counting in passthru mode

[Simon Horman]

On Mon, Oct 26, 2026 at 07:46:35PM -0700, Prasad Koya wrote:
> Enabling allmulticast on a down passthru macvlan, bringing it up,
> then toggling allmulticast off and on can underflow the lower device's
> allmulti reference count.
> 
> macvlan_change_rx_flags() only propagates IFF_ALLMULTI changes while
> the macvlan is up. However, the passthru path in macvlan_open() skips
> taking an allmulti reference when IFF_ALLMULTI is already set.
> Clearing allmulticast after opening the device therefore decrements
> a reference that was never taken. With no other allmulti users, the
> unsigned counter wraps from zero to UINT_MAX. The next increment
> fails with -EOVERFLOW and reports "allmulti touches roof".
> 

Hi Prasad,

A Fixes tag should go here.
(No blank line between it and your Signed-off-by line).

There is no need to repost just to address this.
Replying with the Fixes tag should be sufficient.

> Signed-off-by: Prasad Koya <prasad@arista.com>
> ---
> Reproducer:
> 
>   #!/bin/bash
>   set -euo pipefail
> 
>   ns=allmulti-test
>   host=am-veth0
>   peer=am-veth1
>   mv=am-mv0
> 
>   cleanup()
>   {
>       ip netns del "$ns" 2>/dev/null || true
>   }
>   trap cleanup EXIT
> 
>   ip netns add "$ns"
>   ip link add "$host" type veth peer name "$peer"
>   ip link set "$peer" netns "$ns"
> 
>   ip link set "$host" up
>   ip -n "$ns" link set lo up
>   ip -n "$ns" link set "$peer" up
> 
>   ip -n "$ns" link add link "$peer" name "$mv" type macvlan mode passthru
> 
>   ip -n "$ns" link set dev "$mv" allmulticast on
>   ip -n "$ns" link set dev "$mv" up
>   ip -n "$ns" link set dev "$mv" allmulticast off
>   ip -n "$ns" link set dev "$mv" allmulticast on
> 
>  drivers/net/macvlan.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
> index afad90b9222a..e20d587453d1 100644
> --- a/drivers/net/macvlan.c
> +++ b/drivers/net/macvlan.c
> @@ -643,6 +643,14 @@ static int macvlan_open(struct net_device *dev)
>  			if (err < 0)
>  				goto out;
>  		}
> +		if (dev->flags & IFF_ALLMULTI) {
> +			err = dev_set_allmulti(lowerdev, 1);
> +			if (err < 0) {
> +				if (!(vlan->flags & MACVLAN_FLAG_NOPROMISC))
> +					dev_set_promiscuity(lowerdev, -1);
> +				goto out;
> +			}
> +		}
>  		goto hash_add;
>  	}
>  
> @@ -713,6 +721,8 @@ static int macvlan_stop(struct net_device *dev)
>  	dev_mc_unsync(lowerdev, dev);
>  
>  	if (macvlan_passthru(vlan->port)) {
> +		if (dev->flags & IFF_ALLMULTI)
> +			dev_set_allmulti(lowerdev, -1);
>  		if (!(vlan->flags & MACVLAN_FLAG_NOPROMISC))
>  			dev_set_promiscuity(lowerdev, -1);
>  		goto hash_del;
> 
> base-commit: 7076f684d5132e6a6145e1da2fa74771ecd052e5
> -- 
> 2.43.0
> 

I'm unsure if it matters, but the order of initialisation of multicast and
promiscuity differs here from the non-pass-through case.

Overall I think the approach you have taken here is appropriate
as a minimal fix for net.

Reviewed-by: Simon Horman <horms@kernel.org>


But I do see that there is growing duplication of code in the
pass-through and non-pass-through paths. And I believe that
is due to the approach taken by the existing code of using
goto to control flow (other than for cleanup in error paths).

In the longer term I think it would be nice to address that.
I took a stab at that. Perhaps I'm overthinking things.
But, FWIIW, this is what I cam up with (compile tested only).

diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index a48c9e662fe9..f2a3cf540e4e 100644
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -631,24 +631,31 @@ static const struct header_ops macvlan_hard_header_ops = {
 	.parse_protocol	= eth_header_parse_protocol,
 };
 
-static int macvlan_open(struct net_device *dev)
+static int macvlan_should_set_promisc(struct net_device *dev)
 {
 	struct macvlan_dev *vlan = netdev_priv(dev);
-	struct net_device *lowerdev = vlan->lowerdev;
-	int err;
 
-	if (macvlan_passthru(vlan->port)) {
-		if (!(vlan->flags & MACVLAN_FLAG_NOPROMISC)) {
-			err = dev_set_promiscuity(lowerdev, 1);
-			if (err < 0)
-				goto out;
-		}
-		goto hash_add;
-	}
+	if (macvlan_passthru(vlan->port))
+		return !(vlan->flags & MACVLAN_FLAG_NOPROMISC);
+
+	return dev->flags & IFF_PROMISC;
+}
+
+/* Initialise acceleration or add unicast address.
+ * Skipped for pass-through ports.
+ */
+static int macvlan_init_vlan(struct net_device *dev)
+{
+	struct macvlan_dev *vlan = netdev_priv(dev);
+	struct net_device *lowerdev;
+
+	if (macvlan_passthru(vlan->port))
+		return 0;
 
-	err = -EADDRINUSE;
 	if (macvlan_addr_busy(vlan->port, dev->dev_addr))
-		goto out;
+		return -EADDRINUSE;
+
+	lowerdev = vlan->lowerdev;
 
 	/* Attempt to populate accel_priv which is used to offload the L2
 	 * forwarding requests for unicast packets.
@@ -661,40 +668,71 @@ static int macvlan_open(struct net_device *dev)
 	 * populated we must add the unicast address to the lower device.
 	 */
 	if (IS_ERR_OR_NULL(vlan->accel_priv)) {
+		int err;
+
 		vlan->accel_priv = NULL;
 		err = dev_uc_add(lowerdev, dev->dev_addr);
 		if (err < 0)
-			goto out;
+			return err;
+	}
+
+	return 0;
+}
+
+/* Clean up acceleration or remove unicast address.
+ * Skipped for pass-through ports.
+ */
+static void macvlan_uninit_vlan(struct net_device *dev)
+{
+	struct macvlan_dev *vlan = netdev_priv(dev);
+	struct net_device *lowerdev;
+
+	if (macvlan_passthru(vlan->port))
+		return;
+
+	lowerdev = vlan->lowerdev;
+
+	if (vlan->accel_priv) {
+		lowerdev->netdev_ops->ndo_dfwd_del_station(lowerdev,
+							   vlan->accel_priv);
+		vlan->accel_priv = NULL;
+	} else {
+		dev_uc_del(lowerdev, dev->dev_addr);
 	}
+}
+
+static int macvlan_open(struct net_device *dev)
+{
+	struct macvlan_dev *vlan = netdev_priv(dev);
+	struct net_device *lowerdev;
+	int err;
+
+	err = macvlan_init_vlan(dev);
+	if (err)
+		return err;
+
+	lowerdev = vlan->lowerdev;
 
 	if (dev->flags & IFF_ALLMULTI) {
 		err = dev_set_allmulti(lowerdev, 1);
 		if (err < 0)
-			goto del_unicast;
+			goto uninit;
 	}
 
-	if (dev->flags & IFF_PROMISC) {
+	if (macvlan_should_set_promisc(dev)) {
 		err = dev_set_promiscuity(lowerdev, 1);
 		if (err < 0)
 			goto clear_multi;
 	}
 
-hash_add:
 	macvlan_hash_add(vlan);
 	return 0;
 
 clear_multi:
 	if (dev->flags & IFF_ALLMULTI)
 		dev_set_allmulti(lowerdev, -1);
-del_unicast:
-	if (vlan->accel_priv) {
-		lowerdev->netdev_ops->ndo_dfwd_del_station(lowerdev,
-							   vlan->accel_priv);
-		vlan->accel_priv = NULL;
-	} else {
-		dev_uc_del(lowerdev, dev->dev_addr);
-	}
-out:
+uninit:
+	macvlan_uninit_vlan(dev);
 	return err;
 }
 
@@ -712,21 +750,15 @@ static int macvlan_stop(struct net_device *dev)
 	dev_uc_unsync(lowerdev, dev);
 	dev_mc_unsync(lowerdev, dev);
 
-	if (macvlan_passthru(vlan->port)) {
-		if (!(vlan->flags & MACVLAN_FLAG_NOPROMISC))
-			dev_set_promiscuity(lowerdev, -1);
-		goto hash_del;
-	}
-
 	if (dev->flags & IFF_ALLMULTI)
 		dev_set_allmulti(lowerdev, -1);
 
-	if (dev->flags & IFF_PROMISC)
+	if (macvlan_should_set_promisc(dev))
 		dev_set_promiscuity(lowerdev, -1);
 
-	dev_uc_del(lowerdev, dev->dev_addr);
+	if (!macvlan_passthru(vlan->port))
+		dev_uc_del(lowerdev, dev->dev_addr);
 
-hash_del:
 	macvlan_hash_del(vlan, !dev->dismantle);
 	return 0;
 }

Re: [PATCH net] macvlan: fix allmulti reference counting in passthru mode

[Prasad Koya]

  Thanks. Please use the following Fixes tag:

  Fixes: bbeb0eadcf9f ("macvlan: Don't propagate IFF_ALLMULTI changes
on down interfaces.")
  Signed-off-by: Prasad Koya <prasad@arista.com>


On Fri, Oct 30, 2026 at 3:15 AM Simon Horman <horms@kernel.org> wrote:
>
> On Mon, Oct 26, 2026 at 07:46:35PM -0700, Prasad Koya wrote:
> > Enabling allmulticast on a down passthru macvlan, bringing it up,
> > then toggling allmulticast off and on can underflow the lower device's
> > allmulti reference count.
> >
> > macvlan_change_rx_flags() only propagates IFF_ALLMULTI changes while
> > the macvlan is up. However, the passthru path in macvlan_open() skips
> > taking an allmulti reference when IFF_ALLMULTI is already set.
> > Clearing allmulticast after opening the device therefore decrements
> > a reference that was never taken. With no other allmulti users, the
> > unsigned counter wraps from zero to UINT_MAX. The next increment
> > fails with -EOVERFLOW and reports "allmulti touches roof".
> >
>
> Hi Prasad,
>
> A Fixes tag should go here.
> (No blank line between it and your Signed-off-by line).
>
> There is no need to repost just to address this.
> Replying with the Fixes tag should be sufficient.
>
> > Signed-off-by: Prasad Koya <prasad@arista.com>
> > ---
> > Reproducer:
> >
> >   #!/bin/bash
> >   set -euo pipefail
> >
> >   ns=allmulti-test
> >   host=am-veth0
> >   peer=am-veth1
> >   mv=am-mv0
> >
> >   cleanup()
> >   {
> >       ip netns del "$ns" 2>/dev/null || true
> >   }
> >   trap cleanup EXIT
> >
> >   ip netns add "$ns"
> >   ip link add "$host" type veth peer name "$peer"
> >   ip link set "$peer" netns "$ns"
> >
> >   ip link set "$host" up
> >   ip -n "$ns" link set lo up
> >   ip -n "$ns" link set "$peer" up
> >
> >   ip -n "$ns" link add link "$peer" name "$mv" type macvlan mode passthru
> >
> >   ip -n "$ns" link set dev "$mv" allmulticast on
> >   ip -n "$ns" link set dev "$mv" up
> >   ip -n "$ns" link set dev "$mv" allmulticast off
> >   ip -n "$ns" link set dev "$mv" allmulticast on
> >
> >  drivers/net/macvlan.c | 10 ++++++++++
> >  1 file changed, 10 insertions(+)
> >
> > diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
> > index afad90b9222a..e20d587453d1 100644
> > --- a/drivers/net/macvlan.c
> > +++ b/drivers/net/macvlan.c
> > @@ -643,6 +643,14 @@ static int macvlan_open(struct net_device *dev)
> >                       if (err < 0)
> >                               goto out;
> >               }
> > +             if (dev->flags & IFF_ALLMULTI) {
> > +                     err = dev_set_allmulti(lowerdev, 1);
> > +                     if (err < 0) {
> > +                             if (!(vlan->flags & MACVLAN_FLAG_NOPROMISC))
> > +                                     dev_set_promiscuity(lowerdev, -1);
> > +                             goto out;
> > +                     }
> > +             }
> >               goto hash_add;
> >       }
> >
> > @@ -713,6 +721,8 @@ static int macvlan_stop(struct net_device *dev)
> >       dev_mc_unsync(lowerdev, dev);
> >
> >       if (macvlan_passthru(vlan->port)) {
> > +             if (dev->flags & IFF_ALLMULTI)
> > +                     dev_set_allmulti(lowerdev, -1);
> >               if (!(vlan->flags & MACVLAN_FLAG_NOPROMISC))
> >                       dev_set_promiscuity(lowerdev, -1);
> >               goto hash_del;
> >
> > base-commit: 7076f684d5132e6a6145e1da2fa74771ecd052e5
> > --
> > 2.43.0
> >
>
> I'm unsure if it matters, but the order of initialisation of multicast and
> promiscuity differs here from the non-pass-through case.
>
> Overall I think the approach you have taken here is appropriate
> as a minimal fix for net.
>
> Reviewed-by: Simon Horman <horms@kernel.org>
>
>
> But I do see that there is growing duplication of code in the
> pass-through and non-pass-through paths. And I believe that
> is due to the approach taken by the existing code of using
> goto to control flow (other than for cleanup in error paths).
>
> In the longer term I think it would be nice to address that.
> I took a stab at that. Perhaps I'm overthinking things.
> But, FWIIW, this is what I cam up with (compile tested only).
>
> diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
> index a48c9e662fe9..f2a3cf540e4e 100644
> --- a/drivers/net/macvlan.c
> +++ b/drivers/net/macvlan.c
> @@ -631,24 +631,31 @@ static const struct header_ops macvlan_hard_header_ops = {
>         .parse_protocol = eth_header_parse_protocol,
>  };
>
> -static int macvlan_open(struct net_device *dev)
> +static int macvlan_should_set_promisc(struct net_device *dev)
>  {
>         struct macvlan_dev *vlan = netdev_priv(dev);
> -       struct net_device *lowerdev = vlan->lowerdev;
> -       int err;
>
> -       if (macvlan_passthru(vlan->port)) {
> -               if (!(vlan->flags & MACVLAN_FLAG_NOPROMISC)) {
> -                       err = dev_set_promiscuity(lowerdev, 1);
> -                       if (err < 0)
> -                               goto out;
> -               }
> -               goto hash_add;
> -       }
> +       if (macvlan_passthru(vlan->port))
> +               return !(vlan->flags & MACVLAN_FLAG_NOPROMISC);
> +
> +       return dev->flags & IFF_PROMISC;
> +}
> +
> +/* Initialise acceleration or add unicast address.
> + * Skipped for pass-through ports.
> + */
> +static int macvlan_init_vlan(struct net_device *dev)
> +{
> +       struct macvlan_dev *vlan = netdev_priv(dev);
> +       struct net_device *lowerdev;
> +
> +       if (macvlan_passthru(vlan->port))
> +               return 0;
>
> -       err = -EADDRINUSE;
>         if (macvlan_addr_busy(vlan->port, dev->dev_addr))
> -               goto out;
> +               return -EADDRINUSE;
> +
> +       lowerdev = vlan->lowerdev;
>
>         /* Attempt to populate accel_priv which is used to offload the L2
>          * forwarding requests for unicast packets.
> @@ -661,40 +668,71 @@ static int macvlan_open(struct net_device *dev)
>          * populated we must add the unicast address to the lower device.
>          */
>         if (IS_ERR_OR_NULL(vlan->accel_priv)) {
> +               int err;
> +
>                 vlan->accel_priv = NULL;
>                 err = dev_uc_add(lowerdev, dev->dev_addr);
>                 if (err < 0)
> -                       goto out;
> +                       return err;
> +       }
> +
> +       return 0;
> +}
> +
> +/* Clean up acceleration or remove unicast address.
> + * Skipped for pass-through ports.
> + */
> +static void macvlan_uninit_vlan(struct net_device *dev)
> +{
> +       struct macvlan_dev *vlan = netdev_priv(dev);
> +       struct net_device *lowerdev;
> +
> +       if (macvlan_passthru(vlan->port))
> +               return;
> +
> +       lowerdev = vlan->lowerdev;
> +
> +       if (vlan->accel_priv) {
> +               lowerdev->netdev_ops->ndo_dfwd_del_station(lowerdev,
> +                                                          vlan->accel_priv);
> +               vlan->accel_priv = NULL;
> +       } else {
> +               dev_uc_del(lowerdev, dev->dev_addr);
>         }
> +}
> +
> +static int macvlan_open(struct net_device *dev)
> +{
> +       struct macvlan_dev *vlan = netdev_priv(dev);
> +       struct net_device *lowerdev;
> +       int err;
> +
> +       err = macvlan_init_vlan(dev);
> +       if (err)
> +               return err;
> +
> +       lowerdev = vlan->lowerdev;
>
>         if (dev->flags & IFF_ALLMULTI) {
>                 err = dev_set_allmulti(lowerdev, 1);
>                 if (err < 0)
> -                       goto del_unicast;
> +                       goto uninit;
>         }
>
> -       if (dev->flags & IFF_PROMISC) {
> +       if (macvlan_should_set_promisc(dev)) {
>                 err = dev_set_promiscuity(lowerdev, 1);
>                 if (err < 0)
>                         goto clear_multi;
>         }
>
> -hash_add:
>         macvlan_hash_add(vlan);
>         return 0;
>
>  clear_multi:
>         if (dev->flags & IFF_ALLMULTI)
>                 dev_set_allmulti(lowerdev, -1);
> -del_unicast:
> -       if (vlan->accel_priv) {
> -               lowerdev->netdev_ops->ndo_dfwd_del_station(lowerdev,
> -                                                          vlan->accel_priv);
> -               vlan->accel_priv = NULL;
> -       } else {
> -               dev_uc_del(lowerdev, dev->dev_addr);
> -       }
> -out:
> +uninit:
> +       macvlan_uninit_vlan(dev);
>         return err;
>  }
>
> @@ -712,21 +750,15 @@ static int macvlan_stop(struct net_device *dev)
>         dev_uc_unsync(lowerdev, dev);
>         dev_mc_unsync(lowerdev, dev);
>
> -       if (macvlan_passthru(vlan->port)) {
> -               if (!(vlan->flags & MACVLAN_FLAG_NOPROMISC))
> -                       dev_set_promiscuity(lowerdev, -1);
> -               goto hash_del;
> -       }
> -
>         if (dev->flags & IFF_ALLMULTI)
>                 dev_set_allmulti(lowerdev, -1);
>
> -       if (dev->flags & IFF_PROMISC)
> +       if (macvlan_should_set_promisc(dev))
>                 dev_set_promiscuity(lowerdev, -1);
>
> -       dev_uc_del(lowerdev, dev->dev_addr);
> +       if (!macvlan_passthru(vlan->port))
> +               dev_uc_del(lowerdev, dev->dev_addr);
>
> -hash_del:
>         macvlan_hash_del(vlan, !dev->dismantle);
>         return 0;
>  }