From 9d6c59eeea88a3e9d7039cb4fed5126ef704593a Mon Sep 17 00:00:00 2001
From: Stanislav Malyshev <stas@php.net>
Date: Sun, 6 Jan 2019 23:31:15 -0800
Subject: [PATCH] Fix bug #77418 - Heap overflow in utf32be_mbc_to_code

---
 NEWS                                  |  7 ++++---
 ext/mbstring/oniguruma/enc/utf16_be.c |  4 +++-
 ext/mbstring/oniguruma/enc/utf16_le.c |  3 ++-
 ext/mbstring/oniguruma/enc/utf32_be.c |  1 +
 ext/mbstring/oniguruma/enc/utf32_le.c |  1 +
 ext/mbstring/tests/bug77418.phpt      | 14 ++++++++++++++
 6 files changed, 25 insertions(+), 5 deletions(-)
 create mode 100644 ext/mbstring/tests/bug77418.phpt

diff --git a/ext/mbstring/oniguruma/enc/utf16_be.c b/ext/mbstring/oniguruma/enc/utf16_be.c
index 1e909ebbf293..9e2f73b0735e 100644
--- a/ext/mbstring/oniguruma/enc/utf16_be.c
+++ b/ext/mbstring/oniguruma/enc/utf16_be.c
@@ -75,16 +75,18 @@ utf16be_is_mbc_newline(const UChar* p, const UChar* end)
 }
 
 static OnigCodePoint
-utf16be_mbc_to_code(const UChar* p, const UChar* end ARG_UNUSED)
+utf16be_mbc_to_code(const UChar* p, const UChar* end)
 {
   OnigCodePoint code;
 
   if (UTF16_IS_SURROGATE_FIRST(*p)) {
+    if (end - p < 4) return 0;
     code = ((((p[0] - 0xd8) << 2) + ((p[1] & 0xc0) >> 6) + 1) << 16)
          + ((((p[1] & 0x3f) << 2) + (p[2] - 0xdc)) << 8)
          + p[3];
   }
   else {
+    if (end - p < 2) return 0;
     code = p[0] * 256 + p[1];
   }
   return code;
diff --git a/ext/mbstring/oniguruma/enc/utf16_le.c b/ext/mbstring/oniguruma/enc/utf16_le.c
index 5cc07591173a..580f8dffa2f4 100644
--- a/ext/mbstring/oniguruma/enc/utf16_le.c
+++ b/ext/mbstring/oniguruma/enc/utf16_le.c
@@ -81,13 +81,14 @@ utf16le_is_mbc_newline(const UChar* p, const UChar* end)
 }
 
 static OnigCodePoint
-utf16le_mbc_to_code(const UChar* p, const UChar* end ARG_UNUSED)
+utf16le_mbc_to_code(const UChar* p, const UChar* end)
 {
   OnigCodePoint code;
   UChar c0 = *p;
   UChar c1 = *(p+1);
 
   if (UTF16_IS_SURROGATE_FIRST(c1)) {
+    if (end - p < 4) return 0;
     code = ((((c1 - 0xd8) << 2) + ((c0  & 0xc0) >> 6) + 1) << 16)
          + ((((c0 & 0x3f) << 2) + (p[3] - 0xdc)) << 8)
          + p[2];
diff --git a/ext/mbstring/oniguruma/enc/utf32_be.c b/ext/mbstring/oniguruma/enc/utf32_be.c
index b4f822607c89..5295f26b1e59 100644
--- a/ext/mbstring/oniguruma/enc/utf32_be.c
+++ b/ext/mbstring/oniguruma/enc/utf32_be.c
@@ -60,6 +60,7 @@ utf32be_is_mbc_newline(const UChar* p, const UChar* end)
 static OnigCodePoint
 utf32be_mbc_to_code(const UChar* p, const UChar* end ARG_UNUSED)
 {
+  if (end - p < 4) return 0;
   return (OnigCodePoint )(((p[0] * 256 + p[1]) * 256 + p[2]) * 256 + p[3]);
 }
 
diff --git a/ext/mbstring/oniguruma/enc/utf32_le.c b/ext/mbstring/oniguruma/enc/utf32_le.c
index 8f413bfc74e1..a78c4d0abcc7 100644
--- a/ext/mbstring/oniguruma/enc/utf32_le.c
+++ b/ext/mbstring/oniguruma/enc/utf32_le.c
@@ -60,6 +60,7 @@ utf32le_is_mbc_newline(const UChar* p, const UChar* end)
 static OnigCodePoint
 utf32le_mbc_to_code(const UChar* p, const UChar* end ARG_UNUSED)
 {
+  if (end - p < 4) return 0;
   return (OnigCodePoint )(((p[3] * 256 + p[2]) * 256 + p[1]) * 256 + p[0]);
 }
 
diff --git a/ext/mbstring/tests/bug77418.phpt b/ext/mbstring/tests/bug77418.phpt
new file mode 100644
index 000000000000..b4acc45c2117
--- /dev/null
+++ b/ext/mbstring/tests/bug77418.phpt
@@ -0,0 +1,14 @@
+--TEST--
+Bug #77371 (Heap overflow in utf32be_mbc_to_code)
+--SKIPIF--
+<?php extension_loaded('mbstring') or die('skip mbstring not available'); ?>
+--FILE--
+<?php
+mb_regex_encoding("UTF-32");
+var_dump(mb_split("\x00\x00\x00\x5c\x00\x00\x00B","000000000000000000000000000000"));
+?>
+--EXPECT--
+array(1) {
+  [0]=>
+  string(30) "000000000000000000000000000000"
+}