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Date: Sun, 10 Jul 2011 13:32:46 +0300 From: Nir Tzachar <nir.tzachar@...il.com> To: Arnaud Lacombe <lacombar@...il.com> Cc: linux-kbuild@...r.kernel.org, Michal Marek <mmarek@...e.cz>, linux-kernel@...r.kernel.org, Andrej Gelenberg <andrej.gelenberg@....edu> Subject: Re: [PATCH 2/2] kconfig/nconf: prevent segfault on empty menu Hello. On Sun, Jul 10, 2011 at 10:27 AM, Arnaud Lacombe <lacombar@...il.com> wrote: > nconf does not check the validity of the current menu when help is requested > (with either <F2>, '?' or 'h'). This leads to a NULL pointer dereference when an > empty menu is encountered. > > The following reduced testcase exposes the problem: > > config DEP > bool > > menu "FOO" > > config BAR > bool "BAR" > depends on DEP > > endmenu > > Issue will happen when entering menu "FOO" and requesting help. > > nconf is the only front-end which do not filter the validity of the current > menu. Such filter can not really happen beforehand as other key which does not > deals with the current menu might be entered by the user, so just bails out > earlier if we encounter an invalid menu. I do not believe the correct solution is silently ignoring the user's key presses. I think the correct behavior would be to display a nohelp_text window. something like this (untested): show_scroll_win(main_window, nohelp_text); The other patches in the series seem gr8. Cheers. > Cc: Nir Tzachar <nir.tzachar@...il.com> > Cc: Andrej Gelenberg <andrej.gelenberg@....edu> > Reported-by: Andrej Gelenberg <andrej.gelenberg@....edu> > Signed-off-by: Arnaud Lacombe <lacombar@...il.com> > --- > scripts/kconfig/nconf.c | 7 ++++++- > 1 files changed, 6 insertions(+), 1 deletions(-) > > diff --git a/scripts/kconfig/nconf.c b/scripts/kconfig/nconf.c > index 24fc79a..eb9e49d 100644 > --- a/scripts/kconfig/nconf.c > +++ b/scripts/kconfig/nconf.c > @@ -1222,7 +1222,12 @@ static void conf_message_callback(const char *fmt, va_list ap) > > static void show_help(struct menu *menu) > { > - struct gstr help = str_new(); > + struct gstr help; > + > + if (!menu) > + return; > + > + help = str_new(); > menu_get_ext_help(menu, &help); > show_scroll_win(main_window, _(menu_get_prompt(menu)), str_get(&help)); > str_free(&help); > -- > 1.7.3.4.574.g608b.dirty > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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