Hi, On Sun, Jul 10, 2011 at 6:32 AM, Nir Tzachar <nir.tzachar@xxxxxxxxx> wrote: > Hello. > > On Sun, Jul 10, 2011 at 10:27 AM, Arnaud Lacombe <lacombar@xxxxxxxxx> 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); > This would be: show_scroll_win(main_window, _(menu_get_prompt(menu)), nohelp_text); but we would fall back on the original issue as requesting the prompt of an invalid menu does not make sense, so the menu_get_prompt(menu) would still have to be replaced with something valid. It would be nice to come up with a solution valid at least for nconf and mconf. Currently mconf just silently discard the key pressed. To some extend I do not think any frontend should display a menu which has no visible child, but that may require more changes and affect performance... - Arnaud > The other patches in the series seem gr8. > > Cheers. > >> Cc: Nir Tzachar <nir.tzachar@xxxxxxxxx> >> Cc: Andrej Gelenberg <andrej.gelenberg@xxxxxxx> >> Reported-by: Andrej Gelenberg <andrej.gelenberg@xxxxxxx> >> Signed-off-by: Arnaud Lacombe <lacombar@xxxxxxxxx> >> --- >> 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-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html