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In-Reply-To: <mvmzi1a5h39.fsf@suse.de>
From: Paul Pluzhnikov <ppluzhnikov@google.com>
Date: Tue, 08 May 2018 15:11:00 -0000
Message-ID: <CALoOobNzPmK+5fnxF-cFhkGjOuemGaa3GepJZnb_1m38wb-1xA@mail.gmail.com>
Subject: Re: [patch] Fix path length overflow in realpath (BZ#22786)
To: Andreas Schwab <schwab@suse.de>
Cc: "Joseph S. Myers" <joseph@codesourcery.com>, GLIBC Devel <libc-alpha@sourceware.org>
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On Tue, May 8, 2018 at 7:59 AM Andreas Schwab <schwab@suse.de> wrote:

> On Apr 17 2018, Paul Pluzhnikov <ppluzhnikov@google.com> wrote:

> > diff --git a/stdlib/test-bz22786.c b/stdlib/test-bz22786.c
> > new file mode 100644
> > index 0000000000..1b6331ac5c
> > --- /dev/null
> > +++ b/stdlib/test-bz22786.c
> > @@ -0,0 +1,90 @@
> > +/* Bug 22786: test for stack overflow in realpath.

> This is actually a buffer overflow.  Ok with that change.

I am not sure what you mean by that.

The (stack) allocated buffer is large enough, so technically there is no
buffer overflow here (at least not in the sense that "allocated buffer was
too small"). But the stack is not large enough to hold the buffer of that
size.

-- 
Paul Pluzhnikov