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 927763858401; Mon, 31 Jul 2023 15:18:57 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 927763858401
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1690816737;
	bh=xq/wToaa47w4SwKDZfpKFcY0J8j+iuugV63TyGb6qc0=;
	h=From:To:Subject:Date:From;
	b=xxJJbNMXAdWHu8kbtBQ26O53hYuThOrfu8HjUneyv6zaZPTaNMlz+qApG+LtTeppL
	 8aST7SRT+PUwNnmdqATwVlXC0SSCHfe/nUmXLhxgTC/y77DITKFQ2vjI2mN5/e+0Nt
	 OM7zj6RwuQP/CMz86QfqSu8ZPgZNOaLwEMeIjCuE=
From: "gcc at pauldreik dot se" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug libstdc++/110862] New: format out of bands read on format
 string "{0:{0}"
Date: Mon, 31 Jul 2023 15:18:55 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: new
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: libstdc++
X-Bugzilla-Version: 13.2.0
X-Bugzilla-Keywords: 
X-Bugzilla-Severity: normal
X-Bugzilla-Who: gcc at pauldreik dot se
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-110862-4@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=3D110862

            Bug ID: 110862
           Summary: format out of bands read on format string "{0:{0}"
           Product: gcc
           Version: 13.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: gcc at pauldreik dot se
  Target Milestone: ---

The following program with an incorrect format string causes an out of boun=
ds
read when compiled with gcc 13.2:

#include <cstdio>
#include <format>

int main() {
    unsigned short v =3D 0;
    std::puts(std::vformat("{0:{0}", std::make_format_args(v)).c_str());
}

I expected an exception to be thrown.

Link to reproducer:=20
https://godbolt.org/z/WrqxGE1jG=