efi_loader: check time in SetTime()

The UEFI spec prescribes that we check that the timestamp passed to
SetTime() is checked for validity.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

1 files changed, 25 insertions, 1 deletions

diff --git a/lib/efi_loader/efi_runtime.c b/lib/efi_loader/efi_runtime.c
index 058b40a887..2082d1304f 100644
--- a/lib/efi_loader/efi_runtime.c
+++ b/lib/efi_loader/efi_runtime.c
@@ -214,6 +214,30 @@ out:
 #endif
 }
 
+#ifdef CONFIG_DM_RTC
+
+/**
+ * efi_validate_time() - checks if timestamp is valid
+ *
+ * @time:	timestamp to validate
+ * Returns:	0 if timestamp is valid, 1 otherwise
+ */
+static int efi_validate_time(struct efi_time *time)
+{
+	return (!time ||
+		time->year < 1900 || time->year > 9999 ||
+		!time->month || time->month > 12 || !time->day ||
+		time->day > rtc_month_days(time->month - 1, time->year) ||
+		time->hour > 23 || time->minute > 59 || time->second > 59 ||
+		time->nanosecond > 999999999 ||
+		time->daylight &
+		~(EFI_TIME_IN_DAYLIGHT | EFI_TIME_ADJUST_DAYLIGHT) ||
+		((time->timezone < -1440 || time->timezone > 1440) &&
+		time->timezone != EFI_UNSPECIFIED_TIMEZONE));
+}
+
+#endif
+
 /**
  * efi_set_time_boottime() - set current time
  *
@@ -235,7 +259,7 @@ static efi_status_t EFIAPI efi_set_time_boottime(struct efi_time *time)
 
 	EFI_ENTRY("%p", time);
 
-	if (!time) {
+	if (efi_validate_time(time)) {
 		ret = EFI_INVALID_PARAMETER;
 		goto out;
 	}