2022-10-24 06:16:28

by Li zeming

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Subject: [PATCH] lxdialog: menubox: Add malloc allocation judgment

Add menu_item Only when the pointer judges that the pointer is valid
can function code be executed.

Signed-off-by: Li zeming <[email protected]>
---
scripts/kconfig/lxdialog/menubox.c | 53 +++++++++++++++---------------
1 file changed, 27 insertions(+), 26 deletions(-)

diff --git a/scripts/kconfig/lxdialog/menubox.c b/scripts/kconfig/lxdialog/menubox.c
index 58c2f8afe59b..2ae263ad477e 100644
--- a/scripts/kconfig/lxdialog/menubox.c
+++ b/scripts/kconfig/lxdialog/menubox.c
@@ -55,34 +55,35 @@ static void do_print_item(WINDOW * win, const char *item, int line_y,
{
int j;
char *menu_item = malloc(menu_width + 1);
+ if (menu_item) {
+ strncpy(menu_item, item, menu_width - item_x);
+ menu_item[menu_width - item_x] = '\0';
+ j = first_alpha(menu_item, "YyNnMmHh");

- strncpy(menu_item, item, menu_width - item_x);
- menu_item[menu_width - item_x] = '\0';
- j = first_alpha(menu_item, "YyNnMmHh");
-
- /* Clear 'residue' of last item */
- wattrset(win, dlg.menubox.atr);
- wmove(win, line_y, 0);
-#if OLD_NCURSES
- {
- int i;
- for (i = 0; i < menu_width; i++)
- waddch(win, ' ');
- }
-#else
- wclrtoeol(win);
-#endif
- wattrset(win, selected ? dlg.item_selected.atr : dlg.item.atr);
- mvwaddstr(win, line_y, item_x, menu_item);
- if (hotkey) {
- wattrset(win, selected ? dlg.tag_key_selected.atr
- : dlg.tag_key.atr);
- mvwaddch(win, line_y, item_x + j, menu_item[j]);
- }
- if (selected) {
- wmove(win, line_y, item_x + 1);
+ /* Clear 'residue' of last item */
+ wattrset(win, dlg.menubox.atr);
+ wmove(win, line_y, 0);
+ #if OLD_NCURSES
+ {
+ int i;
+ for (i = 0; i < menu_width; i++)
+ waddch(win, ' ');
+ }
+ #else
+ wclrtoeol(win);
+ #endif
+ wattrset(win, selected ? dlg.item_selected.atr : dlg.item.atr);
+ mvwaddstr(win, line_y, item_x, menu_item);
+ if (hotkey) {
+ wattrset(win, selected ? dlg.tag_key_selected.atr
+ : dlg.tag_key.atr);
+ mvwaddch(win, line_y, item_x + j, menu_item[j]);
+ }
+ if (selected) {
+ wmove(win, line_y, item_x + 1);
+ }
+ free(menu_item);
}
- free(menu_item);
wrefresh(win);
}

--
2.18.2


2022-10-24 08:16:15

by Bagas Sanjaya

[permalink] [raw]
Subject: Re: [PATCH] lxdialog: menubox: Add malloc allocation judgment

On Mon, Oct 24, 2022 at 01:56:29PM +0800, Li zeming wrote:
> Add menu_item Only when the pointer judges that the pointer is valid
> can function code be executed.
>

The if block isn't "judgement", but conditional.

What if menu_item fails to be allocated?

--
An old man doll... just what I always wanted! - Clara


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2022-10-24 09:59:54

by Li zeming

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Subject: Re: [PATCH] lxdialog: menubox: Add malloc allocation judgment


If malloc allocation fails, the menu_item pointer cannot be executed, because when the strncpy function is executed, there will be a problem with the null pointer. Adding an if statement should ensure that the allocation fails and will not be executed.

thanks.