From 65120cfc0969fe9ebd3d4d659b610a54a35ae026 Mon Sep 17 00:00:00 2001
From: Dmitry Stogov <dmitry@zend.com>
Date: Wed, 25 Mar 2020 17:31:06 +0300
Subject: [PATCH] Fixed bug #79412 (Opcache chokes and uses 100% CPU on
 specific script).

---
 NEWS                                   |  4 ++++
 ext/opcache/Optimizer/zend_inference.c | 19 ++++++++++++++++---
 ext/opcache/tests/bug79412.phpt        | 25 +++++++++++++++++++++++++
 3 files changed, 45 insertions(+), 3 deletions(-)
 create mode 100644 ext/opcache/tests/bug79412.phpt

diff --git a/NEWS b/NEWS
index ddcebd14fc..edd69bb27a 100644
--- a/NEWS
+++ b/NEWS
@@ -16,6 +16,10 @@ PHP                                                                        NEWS
 - Iconv:
   . Fixed bug #79200 (Some iconv functions cut Windows-1258). (cmb)
 
+- OPcache:
+  . Fixed bug #79412 (Opcache chokes and uses 100% CPU on specific script).
+    (Dmitry)
+
 - SimpleXML:
   . Fixed bug #61597 (SXE properties may lack attributes and content). (cmb)
 
diff --git a/ext/opcache/Optimizer/zend_inference.c b/ext/opcache/Optimizer/zend_inference.c
index a60ecef888..2579d3ff96 100644
--- a/ext/opcache/Optimizer/zend_inference.c
+++ b/ext/opcache/Optimizer/zend_inference.c
@@ -1807,12 +1807,25 @@ static int zend_infer_ranges(const zend_op_array *op_array, zend_ssa *ssa) /* {{
 				}
 			} WHILE_WORKLIST_END();
 
-			/* Add all SCC entry variables into worklist for narrowing */
+			/* initialize missing ranges */
 			for (j = scc_var[scc]; j >= 0; j = next_scc_var[j]) {
 				if (!ssa->var_info[j].has_range) {
 					zend_inference_init_range(op_array, ssa, j, 1, ZEND_LONG_MIN, ZEND_LONG_MAX, 1);
-				} else if (ssa->vars[j].definition_phi &&
-				           ssa->vars[j].definition_phi->pi < 0) {
+					FOR_EACH_VAR_USAGE(j, ADD_SCC_VAR);
+				}
+			}
+
+			/* widening (second round) */
+			WHILE_WORKLIST(worklist, worklist_len, j) {
+				if (zend_ssa_range_widening(op_array, ssa, j, scc)) {
+					FOR_EACH_VAR_USAGE(j, ADD_SCC_VAR);
+				}
+			} WHILE_WORKLIST_END();
+
+			/* Add all SCC entry variables into worklist for narrowing */
+			for (j = scc_var[scc]; j >= 0; j = next_scc_var[j]) {
+				if (ssa->vars[j].definition_phi
+				 && ssa->vars[j].definition_phi->pi < 0) {
 					/* narrowing Phi functions first */
 					zend_ssa_range_narrowing(op_array, ssa, j, scc);
 				}
diff --git a/ext/opcache/tests/bug79412.phpt b/ext/opcache/tests/bug79412.phpt
new file mode 100644
index 0000000000..20fb0a5ba9
--- /dev/null
+++ b/ext/opcache/tests/bug79412.phpt
@@ -0,0 +1,25 @@
+--TEST--
+Bug #79412 (Opcache chokes and uses 100% CPU on specific script)
+--INI--
+opcache.enable=1
+opcache.optimization_level=-1
+--SKIPIF--
+<?php require_once('skipif.inc'); ?>
+--FILE--
+<?php
+$limitPerRun = 10;
+foreach ($foo as $bar) {
+    $count = 0;
+    foreach ($runs as $run) {
+        ++$count;
+        if ($count >= $limitPerRun) {
+            break;
+        }
+    }
+    foo($limitPerRun);
+}
+?>
+--EXPECTF--
+Notice: Undefined variable: foo in %s on line %d
+
+Warning: Invalid argument supplied for foreach() in %s on line %d
-- 
2.49.0