Re: [Mlterm-dev-en] Segfault on Red Hat 9 plus patch.

[Araki K. <ara...@us...>]

Hi,

Subject: [Mlterm-dev-en] Segfault on Red Hat 9 plus patch.
From: Peter Haight <pe...@sa...>
Message-ID: <200...@wa...>
Date: Mon, 13 Oct 2003 13:51:16 -0700

> I was getting a segfault everytime I started mlterm on Red Hat 9. I tracked
> the problem down to a memory overflow bug in xwindow/x_font_cache.c. On my
> system, in x_get_font_name_list_for_fontset, all of the custom font
> functions return null. So when we get down to the realloc line,
> font_name_list is null. This means that realloc completeley alocates a new
> uninitialized memory block which isn't necessary all zeros. In my case it
> was a long list of ???? which caused it to overwrite some other memory which
> caused a crash later on. 

Thanks:D
Actually I've already fixed the codes in CVS-head in a different point of view.
But, stupidly, I didn't notice that they could cause such a serious problem.
Oops...

I'll soon release 2.8.1.

> Anyway, here's a patch. I did sort of a minimal patch, but I highly
> recommend always using snprintf instead of sprintf in the future which would
> probably have made this bug easier to find.

I don't know why snprintf makes it easier to find such a bug(because the buggy
codes will work anyway by snprintf, maybe), but I agree snprintf is safer in
this situation too.
The problem is that snprintf is a not portable function, I'll replace sprintf
with a wrapper function kik_snprintf.

Regards,
--
Araki Ken
ara...@us...