From c6e34d91b88638966662caac62c4d0e90538e317 Mon Sep 17 00:00:00 2001
From: Stanislav Malyshev <stas@php.net>
Date: Sat, 29 Dec 2018 20:06:08 -0800
Subject: [PATCH] Fix bug #77371 (heap buffer overflow in mb regex functions -
 compile_string_node)

---
 ext/mbstring/oniguruma/regcomp.c |  1 +
 ext/mbstring/tests/bug77371.phpt | 10 ++++++++++
 2 files changed, 11 insertions(+)
 create mode 100644 ext/mbstring/tests/bug77371.phpt

diff --git a/ext/mbstring/oniguruma/regcomp.c b/ext/mbstring/oniguruma/regcomp.c
index b93ca948a773..c72d65d6942f 100644
--- a/ext/mbstring/oniguruma/regcomp.c
+++ b/ext/mbstring/oniguruma/regcomp.c
@@ -524,6 +524,7 @@ compile_string_node(Node* node, regex_t* reg)
 
   for (; p < end; ) {
     len = enclen(enc, p);
+    if (p + len > end) len = end - p;
     if (len == prev_len) {
       slen++;
     }
diff --git a/ext/mbstring/tests/bug77371.phpt b/ext/mbstring/tests/bug77371.phpt
new file mode 100644
index 000000000000..f23445bd0917
--- /dev/null
+++ b/ext/mbstring/tests/bug77371.phpt
@@ -0,0 +1,10 @@
+--TEST--
+Bug #77371 (heap buffer overflow in mb regex functions - compile_string_node)
+--SKIPIF--
+<?php extension_loaded('mbstring') or die('skip mbstring not available'); ?>
+--FILE--
+<?php
+var_dump(mb_ereg("()0\xfc00000\xfc00000\xfc00000\xfc",""))
+?>
+--EXPECT--
+bool(false)
\ No newline at end of file