From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugzilla@gcc.gnu.org>
Received: by sourceware.org (Postfix, from userid 48)
	id 3CFD83858C2B; Sat,  5 Nov 2022 00:56:09 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 3CFD83858C2B
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1667609769;
	bh=DTwgbeX5AeAX8DnEJxLUEh/CahuMaeE0NthnlEo5FJU=;
	h=From:To:Subject:Date:From;
	b=sHRRAc0ILGBa4BrScxPce26XJV1L/yo+twJFWkYCe/fJNMqbts1zFP3ID5IUvHz8H
	 6DjXsGJhkHEDMzkULxWzptHKobMkUht6EFmnCDWrqab7nL4wdHajXQNh99hv3EO3ny
	 izeUojxGIszHXtCjlCXdTRoR9F9rdWvsEHipZGKY=
From: "vanyacpp at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/107528] New: constexpr evaluator doesn't check for
 deallocate of mismatched size
Date: Sat, 05 Nov 2022 00:56:08 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: new
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: c++
X-Bugzilla-Version: 13.0
X-Bugzilla-Keywords: 
X-Bugzilla-Severity: normal
X-Bugzilla-Who: vanyacpp at gmail dot com
X-Bugzilla-Status: UNCONFIRMED
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org
X-Bugzilla-Target-Milestone: ---
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: bug_id short_desc product version bug_status
 bug_severity priority component assigned_to reporter target_milestone
Message-ID: <bug-107528-4@http.gcc.gnu.org/bugzilla/>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/
Auto-Submitted: auto-generated
MIME-Version: 1.0
List-Id: <gcc-bugs.sourceware.org>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D107528

            Bug ID: 107528
           Summary: constexpr evaluator doesn't check for deallocate of
                    mismatched size
           Product: gcc
           Version: 13.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: vanyacpp at gmail dot com
  Target Milestone: ---

This functions causes undefined behavior and should not be evaluated at
compile-time.

The problem is the second argument of `deallocate` function (number of obje=
cts
to deallocate). It must be equal to the number of objects that were allocat=
ed.

#include <memory>

constexpr int foo()
{
    std::allocator<int> alloc;
    int* p =3D alloc.allocate(1);
    alloc.deallocate(p, 3);
    return 42;
}

static_assert(foo() =3D=3D 42);=