[4.2.x] Fixed CVE-2026-1207 -- Prevented SQL injections in RasterField lookups via band index.

Thanks Tarek Nakkouch for the report, and Simon Charette for the initial
triage and review.

Backport of 81aa5292967cd09319c45fe2c1a525ce7b6684d8 from main.

1 files changed, 46 insertions, 1 deletions

diff --git a/tests/gis_tests/rasterapp/test_rasterfield.py b/tests/gis_tests/rasterapp/test_rasterfield.py
index 3f2ce770a9..89c4ec4856 100644
--- a/tests/gis_tests/rasterapp/test_rasterfield.py
+++ b/tests/gis_tests/rasterapp/test_rasterfield.py
@@ -2,7 +2,11 @@ import json
 
 from django.contrib.gis.db.models.fields import BaseSpatialField
 from django.contrib.gis.db.models.functions import Distance
-from django.contrib.gis.db.models.lookups import DistanceLookupBase, GISLookup
+from django.contrib.gis.db.models.lookups import (
+    DistanceLookupBase,
+    GISLookup,
+    RasterBandTransform,
+)
 from django.contrib.gis.gdal import GDALRaster
 from django.contrib.gis.geos import GEOSGeometry
 from django.contrib.gis.measure import D
@@ -356,6 +360,47 @@ class RasterFieldTest(TransactionTestCase):
         with self.assertRaisesMessage(ValueError, msg):
             qs.count()
 
+    def test_lookup_invalid_band_rhs(self):
+        rast = GDALRaster(json.loads(JSON_RASTER))
+        qs = RasterModel.objects.filter(rast__contains=(rast, "evil"))
+        msg = "Band index must be an integer, but got 'str'."
+        with self.assertRaisesMessage(TypeError, msg):
+            qs.count()
+
+    def test_lookup_invalid_band_lhs(self):
+        """
+        Typical left-hand side usage is protected against non-integers, but for
+        defense-in-depth purposes, construct custom lookups that evade the
+        `int()` and `+ 1` checks in the lookups shipped by django.contrib.gis.
+        """
+
+        # Evade the int() call in RasterField.get_transform().
+        class MyRasterBandTransform(RasterBandTransform):
+            band_index = "evil"
+
+            def process_band_indices(self, *args, **kwargs):
+                self.band_lhs = self.lhs.band_index
+                self.band_rhs, *self.rhs_params = self.rhs_params
+
+        # Evade the `+ 1` call in BaseSpatialField.process_band_indices().
+        ContainsLookup = RasterModel._meta.get_field("rast").get_lookup("contains")
+
+        class MyContainsLookup(ContainsLookup):
+            def process_band_indices(self, *args, **kwargs):
+                self.band_lhs = self.lhs.band_index
+                self.band_rhs, *self.rhs_params = self.rhs_params
+
+        RasterField = RasterModel._meta.get_field("rast")
+        RasterField.register_lookup(MyContainsLookup, "contains")
+        self.addCleanup(RasterField.register_lookup, ContainsLookup, "contains")
+
+        qs = RasterModel.objects.annotate(
+            transformed=MyRasterBandTransform("rast")
+        ).filter(transformed__contains=(F("transformed"), 1))
+        msg = "Band index must be an integer, but got 'str'."
+        with self.assertRaisesMessage(TypeError, msg):
+            list(qs)
+
     def test_isvalid_lookup_with_raster_error(self):
         qs = RasterModel.objects.filter(rast__isvalid=True)
         msg = (