[1.8] Fix kafka bound checks (#1172)

grafana · Sep 17, 2024 · 98352a7 · 98352a7
1 parent 166d284
commit 98352a7
Show file tree

Hide file tree

Showing 2 changed files with 12 additions and 3 deletions.
diff --git a/pkg/internal/ebpf/common/kafka_detect_transform.go b/pkg/internal/ebpf/common/kafka_detect_transform.go
@@ -206,7 +206,7 @@ func getTopicName(pkt []byte, offset int, op Operation, apiVersion int16) (strin
 	}
 
 	offset += 4
-	if offset > len(pkt) {
+	if offset >= len(pkt) {
 		return "", errors.New("invalid buffer length")
 	}
 	topicNameSize, err := getTopicNameSize(pkt, offset, op, apiVersion)
@@ -215,7 +215,7 @@ func getTopicName(pkt []byte, offset int, op Operation, apiVersion int16) (strin
 	}
 	offset += 2
 
-	if offset > len(pkt) {
+	if offset >= len(pkt) {
 		return "", nil
 	}
 	maxLen := offset + topicNameSize
@@ -253,7 +253,7 @@ func getTopicNameSize(pkt []byte, offset int, op Operation, apiVersion int16) (i
 		if err != nil {
 			return 0, err
 		}
-	} else {
+	} else if offset < len(pkt) {
 		topicNameSize = int(binary.BigEndian.Uint16(pkt[offset:]))
 	}
 	if topicNameSize <= 0 {

diff --git a/pkg/internal/ebpf/common/kafka_detect_transform_test.go b/pkg/internal/ebpf/common/kafka_detect_transform_test.go
@@ -13,6 +13,15 @@ func TestProcessKafkaRequest(t *testing.T) {
 		input    []byte
 		expected *KafkaInfo
 	}{
+		{
+			name:  "Fetch request (v11) truncated",
+			input: []byte{0, 0, 0, 94, 0, 1, 0, 11, 0, 0, 0, 224, 0, 6, 115, 97, 114, 97, 109, 97, 255, 255, 255, 255, 0, 0, 1, 244, 0, 0, 0, 1, 6, 64, 0, 0, 0, 0, 0, 0, 0, 255, 255, 255, 255, 0, 0, 0, 1},
+			expected: &KafkaInfo{
+				ClientID:    "sarama",
+				Operation:   Fetch,
+				TopicOffset: 45,
+			},
+		},
 		{
 			name:  "Fetch request (v11)",
 			input: []byte{0, 0, 0, 94, 0, 1, 0, 11, 0, 0, 0, 224, 0, 6, 115, 97, 114, 97, 109, 97, 255, 255, 255, 255, 0, 0, 1, 244, 0, 0, 0, 1, 6, 64, 0, 0, 0, 0, 0, 0, 0, 255, 255, 255, 255, 0, 0, 0, 1, 0, 9, 105, 109, 112, 111, 114, 116, 97, 110, 116, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 19, 0, 0, 0, 0, 0, 0, 0, 0, 0, 16, 0, 0, 0, 0, 0, 0, 0, 0},