Date: Sat, 19 Oct 1996 11:15:27 +1000 From: Bruce Evans <bde@zeta.org.au> To: bde@zeta.org.au, tridge@arvidsjaur.anu.edu.au Cc: freebsd-hackers@FreeBSD.org, Guido.vanRooij@nl.cis.philips.com, julian@whistle.com Subject: Re: fix for symlinks in /tmp (fwd) FYI Message-ID: <199610190115.LAA27084@godzilla.zeta.org.au>
next in thread | raw e-mail | index | archive | help
>> Our mkstemp() and mktemp() use O_EXCL, and gcc seems to use mktemp(),
>> so I think gcc isn't vulnerable.
>
>Really? mktemp() actually creates the file? I thought that was what
>tmpfile() was for.
Oops. I forgot that mktemp() was so braindamaged.
>ahhh, ok, mktemp() calls:
>
> _gettemp(char *path,int *doopen)
>
>and the doopen parameter controls if the open is used to create it
>with O_EXCL set. mktemp() looks like this:
>
>char *
>mktemp(path)
> char *path;
>{
> return(_gettemp(path, (int *)NULL) ? path : (char *)NULL);
>}
>
>so doopen is set to NULL, meaning don't create. This means anyone
>using mktemp() still needs to be careful about setting O_EXCL. Does
>gcc on BSD do this?
Not in FreeBSD.
There is still a race (with a much smaller window) if O_EXCL isn't
used even if symlinks aren't followed.
Bruce
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199610190115.LAA27084>