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 ca5c9b1b95a306633f09421c9b293da9aaf94721..3755ae2f4531f5cd5a72c09822f40f80c022f652 100644 (file)
--- 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 791608ad3db71793d17dd03871afcab3787df6c3..26977ea7e87b01a5ebee47819ea212a7314ac626 100644 (file)
--- 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 (file)
index 0000000..75a7561
--- /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;
+}