logs: reject overflow values in OTEL_BLRP_SCHEDULE_DELAY parsing

Author: MPSAJID

sdk/src/common/env_variables.cc

@@ -97,7 +97,14 @@ static bool GetTimeoutFromString(const char *input, std::chrono::system_clock::d
 
   for (; *input && std::isdigit(*input); ++input)
   {
-    result = result * 10 + (*input - '0');
+    auto digit = (*input - '0');
+
+    if (result > (std::numeric_limits<decltype(result)>::max() - digit) / 10)
+    {
+      // Rejecting overflow as invalid.
+      return false;
+    }
+    result = result * 10 + digit;
   }
 
   if (result == 0)

sdk/test/logs/batch_log_record_processor_test.cc

@@ -429,8 +429,7 @@ TEST_F(BatchLogRecordProcessorTest, TestScheduleDelayInvalidEdgeCasesFromEnv)
     BatchLogRecordProcessorOptions options;
 
     EXPECT_EQ(options.schedule_delay_millis, std::chrono::milliseconds(1000))
-        << "Failed for case: " << tc.description
-        << " (value='" << tc.value << "')";
+        << "Failed for case: " << tc.description << " (value='" << tc.value << "')";
 
     unsetenv("OTEL_BLRP_SCHEDULE_DELAY");
   }