Linux Ethernet Bridging - Apr 2022 - [Bridge] [PATCH net-next] net: bridge: switchdev: check br_vlan_group() return value

br_vlan_group() can return NULL and thus return value must be checked
to avoid dereferencing a NULL pointer.

Fixes: 6284c723d9b9 ("net: bridge: mst: Notify switchdev drivers of VLAN
MSTI migrations")
Signed-off-by: Cl?ment L?ger <clement.leger at bootlin.com>
---
 net/bridge/br_switchdev.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/bridge/br_switchdev.c b/net/bridge/br_switchdev.c
index 81400e0b26ac..8f3d76c751dd 100644
--- a/net/bridge/br_switchdev.c
+++ b/net/bridge/br_switchdev.c
@@ -354,6 +354,8 @@ static int br_switchdev_vlan_attr_replay(struct net_device
*br_dev,
 	attr.orig_dev = br_dev;
 
 	vg = br_vlan_group(br);
+	if (!vg)
+		return 0;
 
 	list_for_each_entry(v, &vg->vlan_list, vlist) {
 		if (v->msti) {
-- 
2.34.1

On 21/04/2022 13:12, Cl?ment L?ger wrote:
> br_vlan_group() can return NULL and thus return value must be checked
> to avoid dereferencing a NULL pointer.
> 
> Fixes: 6284c723d9b9 ("net: bridge: mst: Notify switchdev drivers of
VLAN MSTI migrations")
> Signed-off-by: Cl?ment L?ger <clement.leger at bootlin.com>
> ---
>  net/bridge/br_switchdev.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/net/bridge/br_switchdev.c b/net/bridge/br_switchdev.c
> index 81400e0b26ac..8f3d76c751dd 100644
> --- a/net/bridge/br_switchdev.c
> +++ b/net/bridge/br_switchdev.c
> @@ -354,6 +354,8 @@ static int br_switchdev_vlan_attr_replay(struct
net_device *br_dev,
>  	attr.orig_dev = br_dev;
>  
>  	vg = br_vlan_group(br);
> +	if (!vg)
> +		return 0;
>  
>  	list_for_each_entry(v, &vg->vlan_list, vlist) {
>  		if (v->msti) {

Good catch.
Acked-by: Nikolay Aleksandrov <razor at blackwall.org>

Hello:

This patch was applied to netdev/net.git (master)
by Jakub Kicinski <kuba at kernel.org>:

On Thu, 21 Apr 2022 12:12:47 +0200 you wrote:
> br_vlan_group() can return NULL and thus return value must be checked
> to avoid dereferencing a NULL pointer.
> 
> Fixes: 6284c723d9b9 ("net: bridge: mst: Notify switchdev drivers of
VLAN MSTI migrations")
> Signed-off-by: Cl?ment L?ger <clement.leger at bootlin.com>
> ---
>  net/bridge/br_switchdev.c | 2 ++
>  1 file changed, 2 insertions(+)
Here is the summary with links:
  - [net-next] net: bridge: switchdev: check br_vlan_group() return value
    https://git.kernel.org/netdev/net/c/7f40ea2145d9

You are awesome, thank you!
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