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Autor: Tomasz Torcz
Data:  
Para: dng
Assunto: Re: [DNG] Nasty Linux systemd security bug revealed
On Wed, Jul 21, 2021 at 06:00:15PM +0200, Didier Kryn wrote:
> Le 21/07/2021 à 16:51, Bernard Rosset via Dng a écrit :
> >> https://www.zdnet.com/article/nasty-linux-systemd-security-bug-revealed/
> >
> > I'll be projecting myself here, but I reckon sharing the original
> > source rather than journalistic articles whenever possible is best
> > towards a tech-savvy audience.
> >
> > The source (included in above article) is here:
> > https://blog.qualys.com/vulnerabilities-threat-research/2021/07/20/cve-2021-33910-denial-of-service-stack-exhaustion-in-systemd-pid-1
>
>     The code shows the use of strdupa(). There is a family of functions
> which are extensions of POSIX functions, with the suffix 'a' which
> allocate space for the returned string from the stack. They are very
> convenient for lazy programmer, but (slightly ?) dangerous and do not
> belong to POSIX.
>
>     I've found a discussion between a developper and Lennart Poeterring
> in which LP recommends the addition of this kind of functions in Musl
> libc (which will certainly never happen).


That's amusing thought. strdupa() is in Musl:
http://git.musl-libc.org/cgit/musl/tree/include/string.h#n89
alloca() is there, too:
http://git.musl-libc.org/cgit/musl/tree/include/alloca.h


-- 
Tomasz Torcz              “If you try to upissue this patchset I shall be seeking
tomek@???       an IP-routable hand grenade.”  — Andrew Morton (LKML)