DEF-37554 fix transaction data race: recreate transformation cache on tx.Close()

Author: Ruslan Shmelev

internal/corazawaf/transaction.go

@@ -1642,6 +1642,8 @@ func (tx *Transaction) Close() error {
 			Msg("Transaction finished")
 	}
 
+	tx.transformationCache = map[transformationKey]*transformationValue{}
+
 	if len(errs) == 0 {
 		return nil
 	}

internal/corazawaf/transaction_pool_race_test.go

@@ -0,0 +1,40 @@
+package corazawaf
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+// TestTransactionPoolCacheIsolation verifies that each transaction gets its own cache
+func TestTransactionPoolCacheIsolation(t *testing.T) {
+	waf := NewWAF()
+
+	// Create two transactions
+	tx1, tx2 := waf.NewTransaction(), waf.NewTransaction()
+	assert.Empty(t, tx1.transformationCache)
+	assert.Empty(t, tx2.transformationCache)
+	// put some value in the transformation cache for tx1
+	tk1 := transformationKey{transformationsID: 1}
+	tx1.transformationCache[tk1] = &transformationValue{arg: "bla"}
+	assert.NotEmpty(t, tx1.transformationCache)
+
+	t.Logf("tx1.transformationCache pointer is %p", tx1.transformationCache)
+	t.Logf("tx2.transformationCache pointer is %p", tx2.transformationCache)
+	// close both transactions
+	if err := tx1.Close(); err != nil {
+		t.Fatalf("Failed to close tx1: %s", err.Error())
+	}
+	if err := tx2.Close(); err != nil {
+		t.Fatalf("Failed to close tx2: %s", err.Error())
+	}
+
+	tx3, tx4 := waf.NewTransaction(), waf.NewTransaction()
+	// Compare map pointers using reflection to ensure they are different instances
+	assert.Emptyf(t, tx3.transformationCache,
+		"tx3.transformationCache should be empty for new transactions, but it is not, pointer is %p",
+		tx3.transformationCache)
+	assert.Emptyf(t, tx4.transformationCache,
+		"tx4.transformationCache should be empty for new transactions, but it is not, pointer is %p",
+		tx4.transformationCache)
+}