vxlan_vnifilter_process() parses the message with vni_filter_policy, whose VXLAN_VNIFILTER_ENTRY is a bare NLA_NESTED with no nested policy attached. The entry attributes are therefore validated only later, one entry at a time, by the nla_parse_nested() inside vxlan_process_vni_filter(). Entries are parsed as they are dispatched: in a message whose first entry is valid and whose second is not, the first entry is applied and its RTM_NEWTUNNEL notification sent before the second is rejected.
Link the nest to vni_filter_entry_policy with NLA_POLICY_NESTED() so the whole message is validated up front, before any entry is acted on. A message carrying an invalid entry is now rejected as a unit and installs nothing. This reorders two faults. The nest is validated before the device is looked up and before the vnifilter flag is checked, so a request rejected by the entry policy, aimed at a missing or non-vnifilter device, now returns that policy error where it previously returned -ENODEV or -EOPNOTSUPP. The request was invalid either way; only the errno an operator sees changes. The nla_parse_nested() in vxlan_process_vni_filter() stays: it is what fills the per-entry attribute table the handler reads. It can no longer fail on a message that has reached it. Suggested-by: Jakub Kicinski <[email protected]> Link: https://lore.kernel.org/netdev/[email protected]/ Assisted-by: LLM Signed-off-by: Ali Firas <[email protected]> --- Notes: v3: new patch. Link the nest with NLA_POLICY_NESTED(), as Jakub asked. drivers/net/vxlan/vxlan_vnifilter.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/vxlan/vxlan_vnifilter.c b/drivers/net/vxlan/vxlan_vnifilter.c index dd94085e0886..d391ec579661 100644 --- a/drivers/net/vxlan/vxlan_vnifilter.c +++ b/drivers/net/vxlan/vxlan_vnifilter.c @@ -467,7 +467,7 @@ static const struct nla_policy vni_filter_entry_policy[VXLAN_VNIFILTER_ENTRY_MAX }; static const struct nla_policy vni_filter_policy[VXLAN_VNIFILTER_MAX + 1] = { - [VXLAN_VNIFILTER_ENTRY] = { .type = NLA_NESTED }, + [VXLAN_VNIFILTER_ENTRY] = NLA_POLICY_NESTED(vni_filter_entry_policy), }; static int vxlan_update_default_fdb_entry(struct vxlan_dev *vxlan, __be32 vni, -- 2.53.0
