Re: [PATCH net-next v1] vlan: skip nested type that is not IFLA_VLAN_QOS_MAPPING

From: Paolo Abeni
Date: Thu Jan 18 2024 - 07:19:58 EST


On Wed, 2024-01-17 at 23:38 +0800, Lin Ma wrote:
> In the vlan_changelink function, a loop is used to parse the nested
> attributes IFLA_VLAN_EGRESS_QOS and IFLA_VLAN_INGRESS_QOS in order to
> obtain the struct ifla_vlan_qos_mapping. These two nested attributes are
> checked in the vlan_validate_qos_map function, which calls
> nla_validate_nested_deprecated with the vlan_map_policy.
>
> However, this deprecated validator applies a LIBERAL strictness, allowing
> the presence of an attribute with the type IFLA_VLAN_QOS_UNSPEC.
> Consequently, the loop in vlan_changelink may parse an attribute of type
> IFLA_VLAN_QOS_UNSPEC and believe it carries a payload of
> struct ifla_vlan_qos_mapping, which is not necessarily true.
>
> To address this issue and ensure compatibility, this patch introduces two
> type checks that skip attributes whose type is not IFLA_VLAN_QOS_MAPPING.
>
> Signed-off-by: Lin Ma <linma@xxxxxxxxxx>

Why are you targeting net-next? this looks like a fix suitable for
'net' - with a proper fixes tag.

Cheers,

Paolo