Fix Integer-overflow in base::Time::FromExploded.

base/time/time_win.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 
 // Windows Timer Primer
 //
 // A good article:  http://www.ddj.com/windows/184416651
 // A good mozilla bug:  http://bugzilla.mozilla.org/show_bug.cgi?id=363258
 //
@@ skipping 92 matching lines @@
 // Returns the current value of the performance counter.
 uint64_t QPCNowRaw() {
   LARGE_INTEGER perf_counter_now = {};
   // According to the MSDN documentation for QueryPerformanceCounter(), this
   // will never fail on systems that run XP or later.
   // https://msdn.microsoft.com/library/windows/desktop/ms644904.aspx
   ::QueryPerformanceCounter(&perf_counter_now);
   return perf_counter_now.QuadPart;
 }
 
+bool SafeConvertToWord(int in, WORD* out) {
+  base::CheckedNumeric<WORD> result = in;
+  *out = result.ValueOrDefault(std::numeric_limits<WORD>::max());
+  return result.IsValid();
+}
+
 }  // namespace
 
 // Time -----------------------------------------------------------------------
 
 // The internal representation of Time uses FILETIME, whose epoch is 1601-01-01
 // 00:00:00 UTC.  ((1970-1601)*365+89)*24*60*60*1000*1000, where 89 is the
 // number of leap year days between 1601 and 1970: (1970-1601)/4 excluding
 // 1700, 1800, and 1900.
 // static
 const int64_t Time::kTimeTToMicrosecondsOffset = INT64_C(11644473600000000);
@@ skipping 108 matching lines @@
 
 // static
 bool Time::IsHighResolutionTimerInUse() {
   base::AutoLock lock(g_high_res_lock.Get());
   return g_high_res_timer_enabled && g_high_res_timer_count > 0;
 }
 
 // static
 bool Time::FromExploded(bool is_local, const Exploded& exploded, Time* time) {
   // Create the system struct representing our exploded time. It will either be
-  // in local time or UTC.
+  // in local time or UTC.If casting from int to WORD results in overflow,
+  // fail and return Time(0).
   SYSTEMTIME st;
-  st.wYear = static_cast<WORD>(exploded.year);
-  st.wMonth = static_cast<WORD>(exploded.month);
-  st.wDayOfWeek = static_cast<WORD>(exploded.day_of_week);
-  st.wDay = static_cast<WORD>(exploded.day_of_month);
-  st.wHour = static_cast<WORD>(exploded.hour);
-  st.wMinute = static_cast<WORD>(exploded.minute);
-  st.wSecond = static_cast<WORD>(exploded.second);
-  st.wMilliseconds = static_cast<WORD>(exploded.millisecond);
+  if (!SafeConvertToWord(exploded.year, &st.wYear) ||
+      !SafeConvertToWord(exploded.month, &st.wMonth) ||
+      !SafeConvertToWord(exploded.day_of_week, &st.wDayOfWeek) ||
+      !SafeConvertToWord(exploded.day_of_month, &st.wDay) ||
+      !SafeConvertToWord(exploded.hour, &st.wHour) ||
+      !SafeConvertToWord(exploded.minute, &st.wMinute) ||
+      !SafeConvertToWord(exploded.second, &st.wSecond) ||
+      !SafeConvertToWord(exploded.millisecond, &st.wMilliseconds)) {
+    *time = base::Time(0);
+    return false;
+  }
 
   FILETIME ft;
   bool success = true;
   // Ensure that it's in UTC.
   if (is_local) {
     SYSTEMTIME utc_st;
     success = TzSpecificLocalTimeToSystemTime(nullptr, &st, &utc_st) &&
               SystemTimeToFileTime(&utc_st, &ft);
   } else {
     success = !!SystemTimeToFileTime(&st, &ft);
@@ skipping 403 matching lines @@
 TimeTicks TimeTicks::FromQPCValue(LONGLONG qpc_value) {
   return TimeTicks() + QPCValueToTimeDelta(qpc_value);
 }
 
 // TimeDelta ------------------------------------------------------------------
 
 // static
 TimeDelta TimeDelta::FromQPCValue(LONGLONG qpc_value) {
   return QPCValueToTimeDelta(qpc_value);
 }