SERVER-39612 better validation for fields in geoNear

1 files changed, 60 insertions, 0 deletions

diff --git a/jstests/aggregation/sources/geonear/geonear_validation.js b/jstests/aggregation/sources/geonear/geonear_validation.js
new file mode 100644
index 00000000000..d567102762e
--- /dev/null
+++ b/jstests/aggregation/sources/geonear/geonear_validation.js
@@ -0,0 +1,60 @@
+// Test for the bug found in SERVER-39612, where the server could behave poorly on invalid input
+// from a $geoNear.
+(function() {
+    const coll = db.geonear_validation;
+
+    coll.drop();
+    coll.insert({});
+    coll.createIndex({"a.b.c": "2dsphere"});
+
+    function runGeoNearWithKey(key) {
+        return coll.aggregate([{
+            $geoNear: {
+                key: key,
+                spherical: true,
+                distanceField: 'distance',
+                near: {type: 'Point', coordinates: [0, 0]}
+            }
+        }]);
+    }
+
+    function runGeoNearCmdWithKey(key) {
+        const geoCmd = {
+            geoNear: coll.getName(),
+            near: {type: 'Point', coordinates: [0, 0]},
+            spherical: true,
+            key: key
+        };
+        return db.runCommand(geoCmd);
+    }
+
+    // Try a valid value for 'key'.
+    (function() {
+        const key = "a.b.c";
+        const cursor = runGeoNearWithKey(key);
+        assert.eq(cursor.itcount(), 0);
+
+        const cmdCursor = assert.commandWorked(runGeoNearCmdWithKey(key));
+        assert.eq(cursor.itcount(), 0);
+    })();
+
+    (function() {
+        // 'key' cannot start with a "$" since it would be an invalid field name.
+        const key = "$hello";
+        const code = 16410;
+        let err = assert.throws(() => runGeoNearWithKey(key));
+        assert.eq(err.code, code);
+
+        assert.commandFailedWithCode(runGeoNearCmdWithKey(key), code);
+    })();
+
+    (function() {
+        // 'key' cannot include null bytes since it would make it an invalid field name.
+        const key = "A\0B";
+        const code = 16411;
+        const err = assert.throws(() => runGeoNearWithKey(key));
+        assert.eq(err.code, code);
+
+        assert.commandFailedWithCode(runGeoNearCmdWithKey(key), code);
+    })();
+})();