Re: [PATCH net] bridge: Fix VLAN reference count problem

[David Miller]

From: Ido Schimmel 
Date: Sun, 25 Feb 2018 21:59:06 +0200

> When a VLAN is added on a port, a reference is taken on the
> corresponding master VLAN entry. If it does not already exist, then it
> is created and a reference taken.
> 
> However, in the second case a reference is not really taken when
> CONFIG_REFCOUNT_FULL is enabled as refcount_inc() is replaced by
> refcount_inc_not_zero().
> 
> Fix this by using refcount_set() on a newly created master VLAN entry.
> 
> Fixes: 251277598596 ("net, bridge: convert net_bridge_vlan.refcnt from 
> atomic_t to refcount_t")
> Signed-off-by: Ido Schimmel 

Applied and queued up for -stable, thanks!

Re: [PATCH net] bridge: Fix VLAN reference count problem

[Nikolay Aleksandrov]

On 25/02/18 21:59, Ido Schimmel wrote:
> When a VLAN is added on a port, a reference is taken on the
> corresponding master VLAN entry. If it does not already exist, then it
> is created and a reference taken.
> 
> However, in the second case a reference is not really taken when
> CONFIG_REFCOUNT_FULL is enabled as refcount_inc() is replaced by
> refcount_inc_not_zero().
> 
> Fix this by using refcount_set() on a newly created master VLAN entry.
> 
> Fixes: 251277598596 ("net, bridge: convert net_bridge_vlan.refcnt from 
> atomic_t to refcount_t")
> Signed-off-by: Ido Schimmel 
> ---
>  net/bridge/br_vlan.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
> index 51935270c651..9896f4975353 100644
> --- a/net/bridge/br_vlan.c
> +++ b/net/bridge/br_vlan.c
> @@ -168,6 +168,8 @@ static struct net_bridge_vlan *br_vlan_get_master(struct 
> net_bridge *br, u16 vid
>   masterv = br_vlan_find(vg, vid);
>   if (WARN_ON(!masterv))
>   return NULL;
> + refcount_set(>refcnt, 1);
> + return masterv;
>   }
>   refcount_inc(>refcnt);
>  
> 

Good catch,

Acked-by: Nikolay Aleksandrov 

[PATCH net] bridge: Fix VLAN reference count problem

[Ido Schimmel]

When a VLAN is added on a port, a reference is taken on the
corresponding master VLAN entry. If it does not already exist, then it
is created and a reference taken.

However, in the second case a reference is not really taken when
CONFIG_REFCOUNT_FULL is enabled as refcount_inc() is replaced by
refcount_inc_not_zero().

Fix this by using refcount_set() on a newly created master VLAN entry.

Fixes: 251277598596 ("net, bridge: convert net_bridge_vlan.refcnt from atomic_t 
to refcount_t")
Signed-off-by: Ido Schimmel 
---
 net/bridge/br_vlan.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
index 51935270c651..9896f4975353 100644
--- a/net/bridge/br_vlan.c
+++ b/net/bridge/br_vlan.c
@@ -168,6 +168,8 @@ static struct net_bridge_vlan *br_vlan_get_master(struct 
net_bridge *br, u16 vid
masterv = br_vlan_find(vg, vid);
if (WARN_ON(!masterv))
return NULL;
+   refcount_set(>refcnt, 1);
+   return masterv;
}
refcount_inc(>refcnt);
 
-- 
2.14.3