Validate format of timeZone

pkg/apis/batch/validation/validation.go

@@ -18,10 +18,12 @@ package validation
 
 import (
 	"fmt"
+	"regexp"
 	"strings"
 	"time"
 
 	"github.com/robfig/cron/v3"
+
 	v1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	unversionedvalidation "k8s.io/apimachinery/pkg/apis/meta/v1/validation"
@@ -502,6 +504,16 @@ func validateScheduleFormat(schedule string, timeZone *string, fldPath *field.Pa
 	return allErrs
 }
 
+// https://data.iana.org/time-zones/theory.html#naming
+// * A name must not be empty, or contain '//', or start or end with '/'.
+// * Do not use the file name components '.' and '..'.
+// * Within a file name component, use only ASCII letters, '.', '-' and '_'.
+// * Do not use digits, as that might create an ambiguity with POSIX TZ strings.
+// * A file name component must not exceed 14 characters or start with '-'
+//
+// 0-9 and + characters are tolerated to accommodate legacy compatibility names
+var validTimeZoneCharacters = regexp.MustCompile(`^[A-Za-z\.\-_0-9+]{1,14}$`)
+
 func validateTimeZone(timeZone *string, fldPath *field.Path) field.ErrorList {
 	allErrs := field.ErrorList{}
 	if timeZone == nil {
@@ -513,6 +525,13 @@ func validateTimeZone(timeZone *string, fldPath *field.Path) field.ErrorList {
 		return allErrs
 	}
 
+	for _, part := range strings.Split(*timeZone, "/") {
+		if part == "." || part == ".." || strings.HasPrefix(part, "-") || !validTimeZoneCharacters.MatchString(part) {
+			allErrs = append(allErrs, field.Invalid(fldPath, timeZone, fmt.Sprintf("unknown time zone %s", *timeZone)))
+			return allErrs
+		}
+	}
+
 	if strings.EqualFold(*timeZone, "Local") {
 		allErrs = append(allErrs, field.Invalid(fldPath, timeZone, "timeZone must be an explicit time zone as defined in https://www.iana.org/time-zones"))
 	}