project-chip · woody-apple · Jul 8, 2022 · Jul 7, 2022 · Jul 7, 2022 · Jul 7, 2022
diff --git a/src/app/clusters/user-label-server/user-label-server.cpp b/src/app/clusters/user-label-server/user-label-server.cpp
@@ -53,6 +53,29 @@ class UserLabelAttrAccess : public AttributeAccessInterface
     CHIP_ERROR WriteLabelList(const ConcreteDataAttributePath & aPath, AttributeValueDecoder & aDecoder);
 };
 
+/// Matches constraints on a LabelStruct.
+bool IsValidLabelEntry(const Structs::LabelStruct::Type & entry)
+{
+    constexpr size_t kMaxLabelSize = 16;
+    constexpr size_t kMaxValueSize = 16;
+
+    // NOTE: spec default for label and value is empty, so empty is accepted here
+    return (entry.label.size() <= kMaxLabelSize) && (entry.value.size() <= kMaxValueSize);
+}
+
+bool IsValidLabelEntryList(const LabelList::TypeInfo::DecodableType & list)
+{
+    auto iter = list.begin();
+    while (iter.Next())
+    {
+        if (!IsValidLabelEntry(iter.GetValue()))
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
 UserLabelAttrAccess gAttrAccess;
 
 CHIP_ERROR UserLabelAttrAccess::ReadLabelList(EndpointId endpoint, AttributeValueEncoder & aEncoder)
@@ -106,6 +129,7 @@ CHIP_ERROR UserLabelAttrAccess::WriteLabelList(const ConcreteDataAttributePath &
         LabelList::TypeInfo::DecodableType decodablelist;
 
         ReturnErrorOnFailure(aDecoder.Decode(decodablelist));
+        ReturnErrorCodeIf(!IsValidLabelEntryList(decodablelist), CHIP_ERROR_INVALID_ARGUMENT);
 
         auto iter = decodablelist.begin();
         while (iter.Next())
@@ -120,7 +144,10 @@ CHIP_ERROR UserLabelAttrAccess::WriteLabelList(const ConcreteDataAttributePath &
     if (aPath.mListOp == ConcreteDataAttributePath::ListOperation::AppendItem)
     {
         Structs::LabelStruct::DecodableType entry;
+
         ReturnErrorOnFailure(aDecoder.Decode(entry));
+        ReturnErrorCodeIf(!IsValidLabelEntry(entry), CHIP_ERROR_INVALID_ARGUMENT);
+
         return provider->AppendUserLabel(endpoint, entry);
     }
 

diff --git a/src/app/tests/suites/TestUserLabelClusterConstraints.yaml b/src/app/tests/suites/TestUserLabelClusterConstraints.yaml
@@ -0,0 +1,57 @@
+# Copyright (c) 2022 Project CHIP Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+name: User Label Cluster Tests
+
+config:
+    nodeId: 0x12344321
+    cluster: "User Label"
+    endpoint: 0
+
+tests:
+    - label: "Wait for the commissioned device to be retrieved"
+      cluster: "DelayCommands"
+      command: "WaitForCommissionee"
+      arguments:
+          values:
+              - name: "nodeId"
+                value: nodeId
+
+    - label: "Attempt to write overly long item for label"
+      command: "writeAttribute"
+      attribute: "label list"
+      arguments:
+          value:
+              [
+                  {
+                      label: "this is longer than sixteen characters",
+                      value: "bedroom 2",
+                  },
+              ]
+      response:
+          error: FAILURE
+
+    - label: "Attempt to write overly long item for value"
+      command: "writeAttribute"
+      attribute: "label list"
+      arguments:
+          value:
+              [
+                  {
+                      label: "test",
+                      value: "this is longer than sixteen characters",
+                  },
+              ]
+      response:
+          error: FAILURE
diff --git a/src/app/tests/suites/tests.js b/src/app/tests/suites/tests.js
@@ -714,6 +714,7 @@ function getTests() {
         "TestSystemCommands",
         "TestBinding",
         "TestUserLabelCluster",
+        "TestUserLabelClusterConstraints",
         "TestArmFailSafe",
         "TestFanControl",
     ];

diff --git a/zzz_generated/chip-tool/zap-generated/test/Commands.h b/zzz_generated/chip-tool/zap-generated/test/Commands.h