Add some limits

util/sprig/defaults.go

@@ -132,7 +132,7 @@ func toRawJSON(v any) string {
 	if err != nil {
 		panic(err)
 	}
-	return string(output)
+	return output
 }
 
 // mustToRawJSON encodes an item into a JSON string with no escaping of HTML characters.

util/sprig/functions.go

@@ -14,6 +14,11 @@ import (
 	"time"
 )
 
+const (
+	loopExecutionLimit = 10_000  // Limit the number of loop executions to prevent execution from taking too long
+	stringLengthLimit  = 100_000 // Limit the length of strings to prevent memory issues
+)
+
 // TxtFuncMap produces the function map.
 //
 // Use this to pass the functions into the template engine:
@@ -58,7 +63,7 @@ var genericMap = map[string]any{
 	},
 	"substr": substring,
 	// Switch order so that "foo" | repeat 5
-	"repeat":     func(count int, str string) string { return strings.Repeat(str, count) },
+	"repeat":     repeat,
 	"trimAll":    func(a, b string) string { return strings.Trim(b, a) },
 	"trimSuffix": func(a, b string) string { return strings.TrimSuffix(b, a) },
 	"trimPrefix": func(a, b string) string { return strings.TrimPrefix(b, a) },

util/sprig/numeric.go

@@ -127,7 +127,15 @@ func until(count int) []int {
 }
 
 func untilStep(start, stop, step int) []int {
-	v := []int{}
+	var v []int
+	if step == 0 {
+		return v
+	}
+
+	iterations := math.Abs(float64(stop)-float64(start)) / float64(step)
+	if iterations > loopExecutionLimit {
+		panic(fmt.Sprintf("too many iterations in untilStep; max allowed is %d, got %f", loopExecutionLimit, iterations))
+	}
 
 	if stop < start {
 		if step >= 0 {

util/sprig/strings.go

@@ -187,3 +187,12 @@ func substring(start, end int, s string) string {
 	}
 	return s[start:end]
 }
+
+func repeat(count int, str string) string {
+	if count > loopExecutionLimit {
+		panic(fmt.Sprintf("repeat count %d exceeds limit of %d", count, loopExecutionLimit))
+	} else if count*len(str) >= stringLengthLimit {
+		panic(fmt.Sprintf("repeat count %d with string length %d exceeds limit of %d", count, len(str), stringLengthLimit))
+	}
+	return strings.Repeat(str, count)
+}