Fix #79015: undefined-behavior in php_date.c

We check that the given microsecond fraction is in the valid range
[0, 1000000[, and otherwise mark it as invalid.  We also drop the
useless do loop; a plain block is sufficient here.

Author: cmb69

NEWS

@@ -10,6 +10,9 @@ PHP                                                                        NEWS
   . Implemented FR #77711 (CURLFile should support UNICODE filenames). (cmb)
   . Fixed bug #79033 (Curl timeout error with specific url and post). (cmb)
 
+- Date:
+  . Fixed bug #79015 (undefined-behavior in php_date.c). (cmb)
+
 - Fileinfo:
   . Fixed bug #74170 (locale information change after mime_content_type).
     (Sergei Turchanov)

ext/date/php_date.c

@@ -4389,14 +4389,16 @@ static int php_date_interval_initialize_from_hash(zval **return_value, php_inter
 	PHP_DATE_INTERVAL_READ_PROPERTY("h", h, timelib_sll, -1)
 	PHP_DATE_INTERVAL_READ_PROPERTY("i", i, timelib_sll, -1)
 	PHP_DATE_INTERVAL_READ_PROPERTY("s", s, timelib_sll, -1)
-	do {
+	{
 		zval *z_arg = zend_hash_str_find(myht, "f", sizeof("f") - 1);
+		(*intobj)->diff->us = -1000000;
 		if (z_arg) {
-			(*intobj)->diff->us = ((double)zval_get_double(z_arg) * 1000000);
-		} else {
-			(*intobj)->diff->us = (double) -1000000;
+			double val = zval_get_double(z_arg) * 1000000;
+			if (val >= 0 && val < 1000000) {
+				(*intobj)->diff->us = val;
+			}
 		}
-	} while (0);
+	}
 	PHP_DATE_INTERVAL_READ_PROPERTY("weekday", weekday, int, -1)
 	PHP_DATE_INTERVAL_READ_PROPERTY("weekday_behavior", weekday_behavior, int, -1)
 	PHP_DATE_INTERVAL_READ_PROPERTY("first_last_day_of", first_last_day_of, int, -1)

ext/date/tests/bug79015.phpt

@@ -0,0 +1,42 @@
+--TEST--
+Bug #79015 (undefined-behavior in php_date.c)
+--FILE--
+<?php
+$payload = 'O:12:"DateInterval":16:{s:1:"y";i:1;s:1:"m";i:0;s:1:"d";i:4;s:1:"h";i:0;s:1:"i";i:0;s:1:"s";i:0;s:1:"f";i:9999999999990;s:7:"weekday";i:0;s:16:"weekday_behavior";i:0;s:17:"first_last_day_of";i:0;s:6:"invert";i:0;s:4:"days";b:0;s:12:"special_type";i:0;s:14:"special_amount";i:0;s:21:"have_weekday_relative";i:0;s:21:"have_special_relative";i:0;}';
+var_dump(unserialize($payload));
+?>
+--EXPECTF--
+object(DateInterval)#%d (16) {
+  ["y"]=>
+  int(1)
+  ["m"]=>
+  int(0)
+  ["d"]=>
+  int(4)
+  ["h"]=>
+  int(0)
+  ["i"]=>
+  int(0)
+  ["s"]=>
+  int(0)
+  ["f"]=>
+  float(-1)
+  ["weekday"]=>
+  int(0)
+  ["weekday_behavior"]=>
+  int(0)
+  ["first_last_day_of"]=>
+  int(0)
+  ["invert"]=>
+  int(0)
+  ["days"]=>
+  bool(false)
+  ["special_type"]=>
+  int(0)
+  ["special_amount"]=>
+  int(0)
+  ["have_weekday_relative"]=>
+  int(0)
+  ["have_special_relative"]=>
+  int(0)
+}