Commit f98ee76955f883abf2ea2a5e5b43deab01734f47

Authored by Arnaud Lacombe
Committed by Michal Marek
1 parent 5416857867

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>

Showing 1 changed file with 6 additions and 1 deletions Side-by-side Diff

scripts/kconfig/nconf.c
... ... @@ -1220,7 +1220,12 @@
1220 1220  
1221 1221 static void show_help(struct menu *menu)
1222 1222 {
1223   - struct gstr help = str_new();
  1223 + struct gstr help;
  1224 +
  1225 + if (!menu)
  1226 + return;
  1227 +
  1228 + help = str_new();
1224 1229 menu_get_ext_help(menu, &help);
1225 1230 show_scroll_win(main_window, _(menu_get_prompt(menu)), str_get(&help));
1226 1231 str_free(&help);