kconfig/nconf: prevent segfault on empty menu
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.
Cc: Nir Tzachar <nir.tzachar@gmail.com>
Cc: Andrej Gelenberg <andrej.gelenberg@udo.edu>
Reported-by: Andrej Gelenberg <andrej.gelenberg@udo.edu>
Signed-off-by: Arnaud Lacombe <lacombar@gmail.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
diff --git a/scripts/kconfig/nconf.c b/scripts/kconfig/nconf.c
index d55666d..d6345df 100644
--- a/scripts/kconfig/nconf.c
+++ b/scripts/kconfig/nconf.c
@@ -1220,7 +1220,12 @@
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);