openvswitch: Stricter validation for the userspace action

This change enhances the robustness of validate_userspace() by ensuring
that all Netlink attributes are fully contained within the parent
attribute. The previous use of nla_parse_nested_deprecated() could
silently skip trailing or malformed attributes, as it stops parsing at
the first invalid entry.

By switching to nla_parse_deprecated_strict(), we make sure only fully
validated attributes are copied for later use.

Signed-off-by: Eelco Chaudron <[email protected]>
Signed-off-by: NipaLocal <nipa@local>

Author: chaudron

net/openvswitch/flow_netlink.c

@@ -3049,7 +3049,8 @@ static int validate_userspace(const struct nlattr *attr)
 	struct nlattr *a[OVS_USERSPACE_ATTR_MAX + 1];
 	int error;
 
-	error = nla_parse_nested_deprecated(a, OVS_USERSPACE_ATTR_MAX, attr,
+	error = nla_parse_deprecated_strict(a, OVS_USERSPACE_ATTR_MAX,
+					    nla_data(attr), nla_len(attr),
 					    userspace_policy, NULL);
 	if (error)
 		return error;