[dm-devel] [PATCH 4/4] multipath: Fix a potential buffer overflow

[Martin Wilck]

On Tue, 2017-06-13 at 12:53 -0700, Bart Van Assche wrote:
> On 06/13/17 12:29, Martin Wilck wrote:
> > how about this simpler patch, as prflag is actually a boolean?
> > 
> > diff --git a/multipathd/cli_handlers.c b/multipathd/cli_handlers.c
> > index 04c73866..c31ebd34 100644
> > --- a/multipathd/cli_handlers.c
> > +++ b/multipathd/cli_handlers.c
> > @@ -1337,7 +1337,7 @@ cli_getprstatus (void * v, char ** reply, int
> > * len, void * data)
> >         memset(*reply,0,2);
> >  
> >  
> > -       sprintf(*reply,"%d",mpp->prflag);
> > +       sprintf(*reply, "%d", !!mpp->prflag);
> >         (*reply)[1]='\0';
> 
> Hello Martin,
> 
> Every sprintf() call requires careful analysis to see whether or not
> it
> triggers a buffer overflow. I really would like to get rid of that
> sprintf() call.

Then we could write

	snprintf(*reply, 2, "%d", !!mpp->prflag);
  
without needing _GNU_SOURCE.

Martin

-- 
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