linux-kernel - Re: [PATCH] kconfig/lxdialog: replace strcpy() with strscpy() in inputbox.c

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAO9wTFi9xEB_G-CwMxDxWbNcNCRHp9ps5sGj2U9w7YZgBzV1rg@mail.gmail.com>
Date: Fri, 25 Jul 2025 15:41:56 +0530
From: Suchit K <suchitkarunakaran@...il.com>
To: Franco Martelli <martellif67@...il.com>
Cc: masahiroy@...nel.org, linux-kbuild@...r.kernel.org, 
	linux-kernel@...r.kernel.org, skhan@...uxfoundation.org
Subject: Re: [PATCH] kconfig/lxdialog: replace strcpy() with strscpy() in inputbox.c

On Fri, 25 Jul 2025 at 15:23, Franco Martelli <martellif67@...il.com> wrote:
>
> On 25/07/25 at 07:59, Suchit Karunakaran wrote:
> > strcpy() performs no bounds checking and can lead to buffer overflows if
> > the input string exceeds the destination buffer size. Replace it with
> > strscpy(), which ensures the input is always NULL-terminated and
> > prevents overflows.
> >
> > Signed-off-by: Suchit Karunakaran <suchitkarunakaran@...il.com>
> > ---
> >   scripts/kconfig/lxdialog/inputbox.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/scripts/kconfig/lxdialog/inputbox.c b/scripts/kconfig/lxdialog/inputbox.c
> > index 3c6e24b20f5b..8880ccaffa0b 100644
> > --- a/scripts/kconfig/lxdialog/inputbox.c
> > +++ b/scripts/kconfig/lxdialog/inputbox.c
> > @@ -40,7 +40,7 @@ int dialog_inputbox(const char *title, const char *prompt, int height, int width
> >       if (!init)
> >               instr[0] = '\0';
> >       else
> > -             strcpy(instr, init);
> > +             strscpy(instr, init, MAX_LEN + 1);
> >
> >   do_resize:
> >       if (getmaxy(stdscr) <= (height - INPUTBOX_HEIGHT_MIN))
>
> perhaps it's better to sanitize the whole code in
> script/kconfig not only in lxdialog/inputbox.c
>
> $ grep -Rn strcpy scripts/kconfig/*
> scripts/kconfig/confdata.c:143: strcpy(depfile_path +
> depfile_prefix_len, name);
> scripts/kconfig/lxdialog/util.c:348:    strcpy(tempstr, prompt);
> scripts/kconfig/lxdialog/inputbox.c:43:         strcpy(instr, init);
> scripts/kconfig/symbol.c:764:   strcpy(val, newval);
> scripts/kconfig/util.c:55:      strcpy(gs.s, "\0");
>
> because the script "checkpatch.pl" emits a warning
> whether strcpy() function is used:
>
> WARNING: Prefer strscpy over strcpy - see:
> https://github.com/KSPP/linux/issues/88
>

Hi Franco, I wanted to get feedback on this first before proceeding
further. If the code change looks good to you, I’ll go ahead and
submit patches for the other places as well. Thanks!