Re: [PATCH] tty: vt: keyboard: do not copy an extra-byte in copy_to_user

From: Ajay Garg
Date: Sat Nov 06 2021 - 16:07:57 EST


On Sun, Nov 7, 2021 at 1:26 AM Pavel Skripkin <paskripkin@xxxxxxxxx> wrote:
>
> On 11/6/21 22:20, Ajay Garg wrote:
> > I vote for David's strscpy "fix", as it is simple, and does away with
> > the dependency on the length of "func_table[kb_func]".
> >
>
> strscpy fix sounds reasonable to me. just to be save in future.
>
> There is only one thing I am wondering about: translation table entries
> are set by user using this struct
>
> struct kbsentry {
> unsigned char kb_func;
> unsigned char kb_string[512];
> };
>
> it means entries cannot be longer than sizeof(kbsentry::kb_string) - 1
> at all. Do we need extra branching with strscpy() or do we need to do
> anything else here?

Hi Pavel,

Please see my latest comments in the last reply.


>
>
>
> With regards,
> Pavel Skripkin