From fd2bcda8b8777b955222644a5ff94417ba510cb2 Mon Sep 17 00:00:00 2001
From: Jason Novinger <jnovinger@gmail.com>
Date: Wed, 26 Mar 2025 12:12:45 -0500
Subject: [PATCH] Fixes #18991: AttributeError: NoneType object has not
 attribute model (#19006)

---
 netbox/dcim/tests/test_api.py | 40 ++++++++++++++++++++++++++++++++++-
 netbox/utilities/fields.py    |  4 ++--
 2 files changed, 41 insertions(+), 3 deletions(-)

diff --git a/netbox/dcim/tests/test_api.py b/netbox/dcim/tests/test_api.py
index 08f93f6ea..b1ed4aca3 100644
--- a/netbox/dcim/tests/test_api.py
+++ b/netbox/dcim/tests/test_api.py
@@ -1,6 +1,6 @@
 import json
 
-from django.test import override_settings
+from django.test import override_settings, tag
 from django.urls import reverse
 from django.utils.translation import gettext as _
 from rest_framework import status
@@ -1904,6 +1904,27 @@ class FrontPortTest(APIViewTestCases.APIViewTestCase):
             },
         ]
 
+    @tag('regression')  # Issue #18991
+    def test_front_port_paths(self):
+        device = Device.objects.first()
+        rear_port = RearPort.objects.create(
+            device=device, name='Rear Port 10', type=PortTypeChoices.TYPE_8P8C
+        )
+        interface1 = Interface.objects.create(device=device, name='Interface 1')
+        front_port = FrontPort.objects.create(
+            device=device,
+            name='Rear Port 10',
+            type=PortTypeChoices.TYPE_8P8C,
+            rear_port=rear_port,
+        )
+        Cable.objects.create(a_terminations=[interface1], b_terminations=[front_port])
+
+        self.add_permissions(f'dcim.view_{self.model._meta.model_name}')
+        url = reverse(f'dcim-api:{self.model._meta.model_name}-paths', kwargs={'pk': front_port.pk})
+        response = self.client.get(url, **self.header)
+
+        self.assertHttpStatus(response, status.HTTP_200_OK)
+
 
 class RearPortTest(APIViewTestCases.APIViewTestCase):
     model = RearPort
@@ -1947,6 +1968,23 @@ class RearPortTest(APIViewTestCases.APIViewTestCase):
             },
         ]
 
+    @tag('regression')  # Issue #18991
+    def test_rear_port_paths(self):
+        device = Device.objects.first()
+        interface1 = Interface.objects.create(device=device, name='Interface 1')
+        rear_port = RearPort.objects.create(
+            device=device,
+            name='Rear Port 10',
+            type=PortTypeChoices.TYPE_8P8C,
+        )
+        Cable.objects.create(a_terminations=[interface1], b_terminations=[rear_port])
+
+        self.add_permissions(f'dcim.view_{self.model._meta.model_name}')
+        url = reverse(f'dcim-api:{self.model._meta.model_name}-paths', kwargs={'pk': rear_port.pk})
+        response = self.client.get(url, **self.header)
+
+        self.assertHttpStatus(response, status.HTTP_200_OK)
+
 
 class ModuleBayTest(APIViewTestCases.APIViewTestCase):
     model = ModuleBay
diff --git a/netbox/utilities/fields.py b/netbox/utilities/fields.py
index 05f61a147..e2814465a 100644
--- a/netbox/utilities/fields.py
+++ b/netbox/utilities/fields.py
@@ -198,9 +198,9 @@ class GenericArrayForeignKey(FieldCacheMixin, models.Field):
     Provide a generic many-to-many relation through an 2d array field
     """
 
-    many_to_many = True
+    many_to_many = False
     many_to_one = False
-    one_to_many = False
+    one_to_many = True
     one_to_one = False
 
     def __init__(self, field, for_concrete_model=True):