Added Env for max decompressed chart size and chart file size limits

Address #30738

Allows the user to set the max decompressed chart and file size limits introduced in v3.17.3 via environment variables

Signed-off-by: Eunan Hardy <25510708+eunanio@users.noreply.github.com>

pkg/chart/v2/loader/archive.go

@@ -27,11 +27,15 @@ import (
 	"os"
 	"path"
 	"regexp"
+	"strconv"
 	"strings"
 
 	chart "helm.sh/helm/v4/pkg/chart/v2"
 )
 
+const MaxChartFileSizeEnv = "HELM_MAX_DECOMPRESSED_FILE_SIZE"
+const MaxChartSizeEnv = "HELM_MAX_DECOMPRESSED_CHART_SIZE"
+
 // MaxDecompressedChartSize is the maximum size of a chart archive that will be
 // decompressed. This is the decompressed size of all the files.
 // The default value is 100 MiB.
@@ -115,6 +119,34 @@ func isGZipApplication(data []byte) bool {
 	return bytes.HasPrefix(data, sig)
 }
 
+// getMaxDecompressedChartSize retrieves the maximum size of a decompressed chart from the environment variable
+func getMaxDecompressedChartSize() int64 {
+	chartSizeEnv, ok := os.LookupEnv(MaxChartSizeEnv)
+	if !ok {
+		return MaxDecompressedChartSize
+	}
+
+	maxSize, err := strconv.ParseInt(chartSizeEnv, 10, 64)
+	if err != nil {
+		return MaxDecompressedChartSize
+	}
+	return maxSize
+}
+
+// getMaxDecompressedFileSize retrieves the maximum size of a decompressed file from the environment variable
+func getMaxDecompressedFileSize() int64 {
+	fileSizeEnv, ok := os.LookupEnv(MaxChartFileSizeEnv)
+	if !ok {
+		return MaxDecompressedFileSize
+	}
+
+	maxSize, err := strconv.ParseInt(fileSizeEnv, 10, 64)
+	if err != nil {
+		return MaxDecompressedFileSize
+	}
+	return maxSize
+}
+
 // LoadArchiveFiles reads in files out of an archive into memory. This function
 // performs important path security checks and should always be used before
 // expanding a tarball
@@ -127,7 +159,14 @@ func LoadArchiveFiles(in io.Reader) ([]*BufferedFile, error) {
 
 	files := []*BufferedFile{}
 	tr := tar.NewReader(unzipped)
-	remainingSize := MaxDecompressedChartSize
+
+	// Set the maximum size of the decompressed chart.
+	maxChartSize := getMaxDecompressedChartSize()
+	remainingSize := maxChartSize
+
+	// Set the maximum size of a single file in the decompressed chart.
+	maxChartFileSize := getMaxDecompressedFileSize()
+
 	for {
 		b := bytes.NewBuffer(nil)
 		hd, err := tr.Next()
@@ -188,11 +227,11 @@ func LoadArchiveFiles(in io.Reader) ([]*BufferedFile, error) {
 		}
 
 		if hd.Size > remainingSize {
-			return nil, fmt.Errorf("decompressed chart is larger than the maximum size %d", MaxDecompressedChartSize)
+			return nil, fmt.Errorf("decompressed chart is larger than the maximum size %d", maxChartSize)
 		}
 
-		if hd.Size > MaxDecompressedFileSize {
+		if hd.Size > maxChartFileSize {
-			return nil, fmt.Errorf("decompressed chart file %q is larger than the maximum file size %d", hd.Name, MaxDecompressedFileSize)
+			return nil, fmt.Errorf("decompressed chart file %q is larger than the maximum file size %d", hd.Name, maxChartFileSize)
 		}
 
 		limitedReader := io.LimitReader(tr, remainingSize)
@@ -208,7 +247,7 @@ func LoadArchiveFiles(in io.Reader) ([]*BufferedFile, error) {
 		// is the one that goes over the limit. It assumes the Size stored in the tar header
 		// is correct, something many applications do.
 		if bytesWritten < hd.Size || remainingSize <= 0 {
-			return nil, fmt.Errorf("decompressed chart is larger than the maximum size %d", MaxDecompressedChartSize)
+			return nil, fmt.Errorf("decompressed chart is larger than the maximum size %d", maxChartSize)
 		}
 
 		data := bytes.TrimPrefix(b.Bytes(), utf8bom)

pkg/chart/v2/loader/directory.go

@@ -99,8 +99,9 @@ func LoadDir(dir string) (*chart.Chart, error) {
 			return fmt.Errorf("cannot load irregular file %s as it has file mode type bits set", name)
 		}
 
-		if fi.Size() > MaxDecompressedFileSize {
+		maxChartFileSize := getMaxDecompressedFileSize()
-			return fmt.Errorf("chart file %q is larger than the maximum file size %d", fi.Name(), MaxDecompressedFileSize)
+		if fi.Size() > maxChartFileSize {
+			return fmt.Errorf("chart file %q is larger than the maximum file size %d", fi.Name(), maxChartFileSize)
 		}
 
 		data, err := os.ReadFile(name)

pkg/cli/environment.go

@@ -89,9 +89,16 @@ type EnvSettings struct {
 	BurstLimit int
 	// QPS is queries per second which may be used to avoid throttling.
 	QPS float32
+	// Max DecompressedChartSize is the maximum size of a chart archive that will be decompressed.
+	MaxDecompressedChartSize int
+	// MaxDecompressedFileSize is the size of the largest file that Helm will attempt to load.
+	MaxDecompressedFileSize int
 }
 
 func New() *EnvSettings {
+	var defaultMaxDecompressedFileSize int = 5 * 1024 * 1024    // Default 5 MiB
+	var defaultMaxDecompressedChartSize int = 100 * 1024 * 1024 // Default 100 MiB
+
 	env := &EnvSettings{
 		namespace:                 os.Getenv("HELM_NAMESPACE"),
 		MaxHistory:                envIntOr("HELM_MAX_HISTORY", defaultMaxHistory),
@@ -109,6 +116,8 @@ func New() *EnvSettings {
 		RepositoryCache:           envOr("HELM_REPOSITORY_CACHE", helmpath.CachePath("repository")),
 		BurstLimit:                envIntOr("HELM_BURST_LIMIT", defaultBurstLimit),
 		QPS:                       envFloat32Or("HELM_QPS", defaultQPS),
+		MaxDecompressedChartSize:  envIntOr("HELM_MAX_DECOMPRESSED_CHART_SIZE", defaultMaxDecompressedChartSize),
+		MaxDecompressedFileSize:   envIntOr("HELM_MAX_DECOMPRESSED_FILE_SIZE", defaultMaxDecompressedFileSize),
 	}
 	env.Debug, _ = strconv.ParseBool(os.Getenv("HELM_DEBUG"))