Re: prevent cal segfault

[Petr Gajdos <pgajdos@suse.cz>]

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On Thu, Mar 12, 2015 at 12:05:28PM +0100, Karel Zak wrote:
> On Thu, Mar 12, 2015 at 09:46:39AM +0100, Petr Gajdos wrote:
> > cal utility segfaults in putp() when setupterm() fails as cal
> > insufficiently checks for setupterm() failure.
> > 
> > $ TERM= cal
> > Segmentation fault
> 
> I'm not able to reproduce this problem. Anyway you're right that the
> current code is pretty fragile and ignore setupterm() return code is
> bad idea.
> 
> I have applied a little bit different patch, please test it in your
> environment. The patch is also in stable/v2.26 (for v2.26.1).
> 
> https://github.com/karelzak/util-linux/commit/2a4b073e8b2d34dfadd8306f7d71957687923bdd

Yes, that works with my original testcase. has_term is better then
*term misuse.

> > --- misc-utils/cal.c.orig	2014-08-26 16:48:45.132654654 +0200
> > +++ misc-utils/cal.c	2015-03-11 14:16:06.075064939 +0100
> > @@ -81,14 +81,22 @@
> >  # endif
> >  # include <term.h>
> >  
> > -static void my_setupterm(const char *term, int fildes, int *errret)
> > +#if defined(HAVE_LIBNCURSES) || defined(HAVE_LIBNCURSESW) || defined(HAVE_LIBTERMCAP)
> > +static const char	*term="";
> > +#endif
> 
> This seems incorrect, you have moved "#if defined" into another "#if".

Ugh, sure. I have sent you older version of the patch, not the one
from comment 6 of referenced bug.

Thanks!
Petr


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