DMARC-Filter:	OpenDMARC Filter v1.4.2 delorie.com 53T5jRfP1282533
Authentication-Results:	delorie.com; dmarc=pass (p=none dis=none) header.from=cygwin.com
Authentication-Results:	delorie.com; spf=pass smtp.mailfrom=cygwin.com
DKIM-Filter:	OpenDKIM Filter v2.11.0 delorie.com 53T5jRfP1282533
Authentication-Results:	delorie.com;
	dkim=pass (1024-bit key, unprotected) header.d=cygwin.com header.i=@cygwin.com header.a=rsa-sha256 header.s=default header.b=MUwnHKMn
X-Recipient:	archive-cygwin AT delorie DOT com
DKIM-Filter:	OpenDKIM Filter v2.11.0 sourceware.org 414E23858D3C
DKIM-Signature:	v=1; a=rsa-sha256; c=relaxed/relaxed; d=cygwin.com;
	s=default; t=1745905525;
	bh=QLnY+EpqSgerrF9r6tJUhqZjRpCyyJ+oWu2ISQb3qIA=;
	h=Date:To:Subject:List-Id:List-Unsubscribe:List-Archive:List-Post:
	List-Help:List-Subscribe:From:Reply-To:From;
	b=MUwnHKMnqkf9/el9dptXoxbVQ2gaYAz1klEDibWr3mexwM69DGtElUWBRTJwQxpXA
	DqWuIwuw7Oe4EIJLSsGJ7UDo7pWJKwZdyNaoxuuzD5xO1RGC9MvZ6vI2k+kfLyC6/q
	z3ohcZ3kZmaYwNyQIJ/8TqUB6njM9LXyLNCWun90=
X-Original-To:	cygwin AT cygwin DOT com
Delivered-To:	cygwin AT cygwin DOT com
DMARC-Filter:	OpenDMARC Filter v1.4.2 sourceware.org 0B56D3858D26
ARC-Filter:	OpenARC Filter v1.0.0 sourceware.org 0B56D3858D26
ARC-Seal:	i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1745905501; cv=none;
	b=F4EgElmBBQbrxouXyPWa+507KXX0BRqewpsUDfomzVxhR/Oq5WVMWMn8sTaZRicQxltOW9I3UTn0hkpdwQYmYdtmpTvQrsY2bMUKjZjAh0a0ptAg69GgtkWvksiEYt5Q287iSc9affJpNAjPDAgPtKZfJYvpDpOxiwb0Ko9/in4=
ARC-Message-Signature:	i=1; a=rsa-sha256; d=sourceware.org; s=key;
	t=1745905501; c=relaxed/simple;
	bh=LctN2sLaB2gRok5Kfa8dYXJB+cP8ud5crtWp3pRaNvw=;
	h=DKIM-Signature:Date:From:To:Subject:Message-ID:MIME-Version;
	b=SNNF6eggnPu/gaS9iE/b3nQBqTsietd2lv73cKwojdT4qPPmipmstYzOGPqxCgzVlyQmGloVr84yqlBWKKUS5DEe6PGX8aifI+uG/YqlTfTk1NQcq1x2grg/0puG/QhzaYkssW80E+wb1CtL+QgiWsOBArvw5ioMvXLaWuwFR4I=
ARC-Authentication-Results:	i=1; server2.sourceware.org
DKIM-Filter:	OpenDKIM Filter v2.11.0 sourceware.org 0B56D3858D26
Date:	Mon, 28 Apr 2025 22:45:00 -0700 (PDT)
X-X-Sender:	jeremyd AT resin DOT csoft DOT net
To:	cygwin AT cygwin DOT com
Subject:	cygwin_conv_path with size 0
Message-ID:	<9c8107b6-a040-d956-2590-ede1517bc2ad@jdrake.com>
MIME-Version:	1.0
X-BeenThere:	cygwin AT cygwin DOT com
X-Mailman-Version:	2.1.30
List-Id:	General Cygwin discussions and problem reports <cygwin.cygwin.com>
List-Archive:	<https://cygwin.com/pipermail/cygwin/>
List-Post:	<mailto:cygwin AT cygwin DOT com>
List-Help:	<mailto:cygwin-request AT cygwin DOT com?subject=help>
List-Subscribe:	<https://cygwin.com/mailman/listinfo/cygwin>,
	<mailto:cygwin-request AT cygwin DOT com?subject=subscribe>
From:	Jeremy Drake via Cygwin <cygwin AT cygwin DOT com>
Reply-To:	Jeremy Drake <cygwin AT jdrake DOT com>
Sender:	"Cygwin" <cygwin-bounces~archive-cygwin=delorie DOT com AT cygwin DOT com>

I was just describing cygwin_conv_path on a rust issue
(https://github.com/rust-lang/backtrace-rs/pull/704).  I was saying that
the pointer `to` is not accessed when `size` is 0, but it turns out on
circa line 4022 in path.cc

to = (void *) wcpcpy ((wchar_t *) to, ro_u_globalroot.Buffer);

This is before `size` is checked and lsiz returned if it was zero, or
ENOSPC set if size is too small, circa line 4060.  This seems like a bug
to me.


-- 
Problem reports:      https://cygwin.com/problems.html
FAQ:                  https://cygwin.com/faq/
Documentation:        https://cygwin.com/docs.html
Unsubscribe info:     https://cygwin.com/ml/#unsubscribe-simple

- Raw text -