From: Jonathan Wakely <jwakely@redhat.com>
Date: Sat, 23 Feb 2019 01:01:56 +0000 (+0000)
Subject: PR libstdc++/89446 fix null pointer dereference in char_traits
X-Git-Tag: releases/gcc-7.5.0~577
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cfba47dda26867813e4349adbc46196d9d1aac1f;p=thirdparty%2Fgcc.git

PR libstdc++/89446 fix null pointer dereference in char_traits

	PR libstdc++/89446
	* include/bits/char_traits.h (__constant_char_array): Check index is
	in range before dereferencing.
	* testsuite/21_strings/basic_string_view/operators/char/89446.cc:
	New test.

From-SVN: r269143
---

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index ca5c9b1b95a3..3755ae2f4531 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,11 @@
+2019-02-22  Jonathan Wakely  <jwakely@redhat.com>
+
+	PR libstdc++/89446
+	* include/bits/char_traits.h (__constant_char_array): Check index is
+	in range before dereferencing.
+	* testsuite/21_strings/basic_string_view/operators/char/89446.cc:
+	New test.
+
 2018-12-24  Iain Sandoe  <iain@sandoe.co.uk>
 
 	Backport from mainline
diff --git a/libstdc++-v3/include/bits/char_traits.h b/libstdc++-v3/include/bits/char_traits.h
index 791608ad3db7..26977ea7e87b 100644
--- a/libstdc++-v3/include/bits/char_traits.h
+++ b/libstdc++-v3/include/bits/char_traits.h
@@ -246,7 +246,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     __constant_char_array_p(const _CharT* __a, size_t __n)
     {
       size_t __i = 0;
-      while (__builtin_constant_p(__a[__i]) && __i < __n)
+      while (__i < __n && __builtin_constant_p(__a[__i]))
 	__i++;
       return __i == __n;
     }
diff --git a/libstdc++-v3/testsuite/21_strings/basic_string_view/operators/char/89446.cc b/libstdc++-v3/testsuite/21_strings/basic_string_view/operators/char/89446.cc
new file mode 100644
index 000000000000..75a75614e12a
--- /dev/null
+++ b/libstdc++-v3/testsuite/21_strings/basic_string_view/operators/char/89446.cc
@@ -0,0 +1,28 @@
+// Copyright (C) 2019 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++17 -fexceptions -fnon-call-exceptions -O1" }
+// { dg-do run { target { powerpc*-*-linux* i?86-*-linux* x86_64-*-linux* } } }
+// { dg-require-effective-target c++1z }
+
+#include <string_view>
+
+int main()
+{
+  std::string_view s1, s2;
+  return s1 != s2;
+}