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

Author: Ruslan Shmelev

internal/corazawaf/transaction.go

@@ -1642,6 +1642,9 @@ func (tx *Transaction) Close() error {
 			Msg("Transaction finished")
 	}
 
+	tx.transformationCache = map[transformationKey]*transformationValue{}
+	tx.variables = *NewTransactionVariables(tx.WAF.persistenceEngine)
+
 	if len(errs) == 0 {
 		return nil
 	}

internal/corazawaf/transaction_pool_race_test.go

@@ -0,0 +1,52 @@
+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 the first transactions
+	tx1 := waf.NewTransaction()
+	assert.Empty(t, tx1.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)
+	// close both transactions
+	if err := tx1.Close(); err != nil {
+		t.Fatalf("Failed to close tx1: %s", err.Error())
+	}
+
+	// Create the second transaction and save its pointer to transformationCache
+	// Create two transactions
+	tx2 := waf.NewTransaction()
+	assert.Empty(t, tx2.transformationCache)
+	// put some value in the transformation cache for tx1
+
+	t.Logf("tx2.transformationCache pointer is %p", tx2.transformationCache)
+	if err := tx2.Close(); err != nil {
+		t.Fatalf("Failed to close tx2: %s", err.Error())
+	}
+
+	tx3, tx4 := waf.NewTransaction(), waf.NewTransaction()
+	//tx1.variables
+
+	t.Logf("\ntx1.transformationCache pointer is %p\n"+
+		"tx2.tranformactionCache pointer is %p\n"+
+		"tx3.tranformactionCache pointer is %p\n"+
+		"tx4.tranformactionCache pointer is %p\n",
+		tx1.transformationCache,
+		tx2.transformationCache,
+		tx3.transformationCache,
+		tx4.transformationCache)
+
+	assert.Empty(t, tx3.transformationCache)
+	assert.Empty(t, tx4.transformationCache)
+}