From: Alexander Monakov <amonakov@ispras.ru>
To: musl@lists.openwall.com
Subject: Re: [PATCH] fix use of pointer after free in unsetenv
Date: Tue, 5 Jan 2016 00:28:12 +0300 (MSK) [thread overview]
Message-ID: <alpine.LNX.2.20.1601050020380.30584@monopod.intra.ispras.ru> (raw)
In-Reply-To: <20160104210528.GX238@brightrain.aerifal.cx>
On Mon, 4 Jan 2016, Rich Felker wrote:
> On Mon, Jan 04, 2016 at 06:47:36PM +0300, Alexander Monakov wrote:
> > On Mon, 4 Jan 2016, Alexander Monakov wrote:
> > > To me the implementation looks weird due to how it restarts scanning __environ
> > > with 'goto again' from position 0 instead of current position. I can propose
> > > the following rewrite (untested):
>
> The "goto again" is for the rare (generally malicious) case of
> duplicate definitions, to ensure that unsetenv removes them all.
Yes, but my point was that rewinding all the way back to i=0 looks odd -- I
understood the need to scan all entries.
> > Hm, there's no need to preserve relative order of env entries, is there?
>
> Yes, there is. If FOO=x and FOO=y both appear in environ[],
> unsetenv("BAR") must not cause getenv("FOO") to change from "x" to
> "y".
Thanks, I did not consider that. I'm curious, is that just from QoI
perspective, or also required somewhere?
Alexander
next prev parent reply other threads:[~2016-01-04 21:28 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-03 23:09 Alexander Cherepanov
2016-01-04 3:05 ` Rich Felker
2016-01-04 10:52 ` Alexander Cherepanov
2016-01-04 11:56 ` Alexander Monakov
2016-01-04 15:47 ` Alexander Monakov
2016-01-04 21:05 ` Rich Felker
2016-01-04 21:28 ` Alexander Monakov [this message]
2016-01-04 21:53 ` Rich Felker
2016-01-04 7:42 ` Markus Wichmann
2016-01-04 11:58 ` Alexander Cherepanov
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