Merge branch 'net-warn-about-attempts-to-register-negative-ifindex'

Jakub Kicinski says:

====================
net: warn about attempts to register negative ifindex

Follow up to the recently posted fix for OvS lacking input
validation:
https://lore.kernel.org/all/20230814203840.2908710-1-kuba@kernel.org/

Warn about negative ifindex more explicitly and misc YNL updates.
====================

Link: https://lore.kernel.org/r/20230814205627.2914583-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Documentation/netlink/specs/ovs_vport.yaml

@@ -81,6 +81,10 @@ attribute-sets:
     name-prefix: ovs-vport-attr-
     enum-name: ovs-vport-attr
     attributes:
+      -
+        name: unspec
+        type: unused
+        value: 0
       -
         name: port-no
         type: u32
@@ -120,6 +124,20 @@ attribute-sets:
 operations:
   name-prefix: ovs-vport-cmd-
   list:
+    -
+      name: new
+      doc: Create a new OVS vport
+      attribute-set: vport
+      fixed-header: ovs-header
+      do:
+        request:
+          attributes:
+            - name
+            - type
+            - upcall-pid
+            - dp-ifindex
+            - ifindex
+            - options
     -
       name: get
       doc: Get / dump OVS vport configuration and state

net/core/dev.c

@@ -9589,6 +9589,11 @@ static int dev_index_reserve(struct net *net, u32 ifindex)
 {
 	int err;
 
+	if (ifindex > INT_MAX) {
+		DEBUG_NET_WARN_ON_ONCE(1);
+		return -EINVAL;
+	}
+
 	if (!ifindex)
 		err = xa_alloc_cyclic(&net->dev_by_index, &ifindex, NULL,
 				      xa_limit_31b, &net->ifindex, GFP_KERNEL);

tools/net/ynl/lib/ynl.py

@@ -395,7 +395,10 @@ class YnlFamily(SpecFamily):
                              self.family.genl_family['mcast'][mcast_name])
 
     def _add_attr(self, space, name, value):
-        attr = self.attr_sets[space][name]
+        try:
+            attr = self.attr_sets[space][name]
+        except KeyError:
+            raise Exception(f"Space '{space}' has no attribute '{name}'")
         nl_type = attr.value
         if attr["type"] == 'nest':
             nl_type |= Netlink.NLA_F_NESTED
@@ -450,7 +453,10 @@ class YnlFamily(SpecFamily):
         attr_space = self.attr_sets[space]
         rsp = dict()
         for attr in attrs:
-            attr_spec = attr_space.attrs_by_val[attr.type]
+            try:
+                attr_spec = attr_space.attrs_by_val[attr.type]
+            except KeyError:
+                raise Exception(f"Space '{space}' has no attribute with value '{attr.type}'")
             if attr_spec["type"] == 'nest':
                 subdict = self._decode(NlAttrs(attr.raw), attr_spec['nested-attributes'])
                 decoded = subdict
@@ -479,7 +485,10 @@ class YnlFamily(SpecFamily):
 
     def _decode_extack_path(self, attrs, attr_set, offset, target):
         for attr in attrs:
-            attr_spec = attr_set.attrs_by_val[attr.type]
+            try:
+                attr_spec = attr_set.attrs_by_val[attr.type]
+            except KeyError:
+                raise Exception(f"Space '{attr_set.name}' has no attribute with value '{attr.type}'")
             if offset > target:
                 break
             if offset == target: