[PATCH] nconfig: prevent segfault on empty menu

Andrej Gelenberg
2011-07-10T02:48:15Z

[-- Attachment #1: Type: text/plain, Size: 351 bytes --]

Hello,

i found and fixed an NULL-dereference bug in nconf tool.

How to reproduce:
1. $ make nconfig
2. disable "Kernel hacking -> Debug Filesystem"
3. go to "General setup -> GCOV-based kernel profiling" and hit F2
it should segfault

Fix: i have added some checks for "struct menu*" to be NULL before it
get dereferenced

Regards,
Andrej Gelenberg

[-- Attachment #2: 0001-nconfig-prevent-segfault-on-empty-menu.patch --]
[-- Type: text/plain, Size: 1881 bytes --]

From 82be343a388a02477ffb0d464e1f2810c61a1fda Mon Sep 17 00:00:00 2001
From: Andrej Gelenberg <andrej.gelenberg@udo.edu>
Date: Sun, 10 Jul 2011 03:44:50 +0200
Subject: [PATCH] nconfig: prevent segfault on empty menu

how to reproduce:
1. $ make nconfig
2. disable "Kernel hacking -> Debug Filesystem"
3. go to "General setup -> GCOV-based kernel profiling" and hit F2
it should segfault

Fix: i have added some checks for "struct menu*" to be NULL bevor it get dereferenced

Signed-off-by: Andrej Gelenberg <andrej.gelenberg@udo.edu>
---
scripts/kconfig/menu.c | 18 ++++++++++--------
1 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/scripts/kconfig/menu.c b/scripts/kconfig/menu.c
index 5fdf10d..6a09cc4 100644
--- a/scripts/kconfig/menu.c
+++ b/scripts/kconfig/menu.c
@@ -425,7 +425,7 @@ void menu_finalize(struct menu *parent)

bool menu_has_prompt(struct menu *menu)
{
- if (!menu->prompt)
+ if ((!menu) || (!menu->prompt))
return false;
return true;
}
@@ -436,7 +436,7 @@ bool menu_is_visible(struct menu *menu)
struct symbol *sym;
tristate visible;

- if (!menu->prompt)
+ if ((!menu) || !menu->prompt)
return false;

if (menu->visibility) {
@@ -470,10 +470,12 @@ bool menu_is_visible(struct menu *menu)

const char *menu_get_prompt(struct menu *menu)
{
- if (menu->prompt)
- return menu->prompt->text;
- else if (menu->sym)
- return menu->sym->name;
+ if (menu) {
+ if (menu->prompt)
+ return menu->prompt->text;
+ else if (menu->sym)
+ return menu->sym->name;
+ }
return NULL;
}

@@ -496,12 +498,12 @@ struct menu *menu_get_parent_menu(struct menu *menu)

bool menu_has_help(struct menu *menu)
{
- return menu->help != NULL;
+ return menu && (menu->help != NULL);
}

const char *menu_get_help(struct menu *menu)
{
- if (menu->help)
+ if (menu && menu->help)
return menu->help;
else
return "";
--
1.7.6