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Date:   Sat, 24 Jul 2021 13:09:31 +0200
From:   Len Baker <len.baker@gmx.com>
To:     Andy Shevchenko <andy.shevchenko@gmail.com>
Cc:     Len Baker <len.baker@gmx.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Phil Reid <preid@electromag.com.au>,
        dri-devel <dri-devel@lists.freedesktop.org>,
        "open list:FRAMEBUFFER LAYER" <linux-fbdev@vger.kernel.org>,
        linux-staging@lists.linux.dev,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] staging/fbtft: Remove all strcpy() uses
Message-ID: <20210724110931.GA4709@titan>
References: <20210718133920.15825-1-len.baker@gmx.com>
 <CAHp75VeEA0=KFsfdjCnBm-b9+F+NnFWJ38nkh+qtb85XdXVWog@mail.gmail.com>
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Hi,

On Sun, Jul 18, 2021 at 10:42:42PM +0300, Andy Shevchenko wrote:
> On Sun, Jul 18, 2021 at 4:43 PM Len Baker <len.baker@gmx.com> wrote:
> >
> > strcpy() performs no bounds checking on the destination buffer. This
> > could result in linear overflows beyond the end of the buffer, leading
> > to all kinds of misbehaviors. The safe replacement is strscpy() but in
> > this case it is simpler to add NULL to the first position since we wan=
t
> > to empty the string.
>
> > This is a previous step in the path to remove the strcpy() function.
>
> Any document behind this (something to read on the site(s) more or
> less affiliated with what is going to happen in the kernel) to read
> background?

This is a task of the KSPP (kernel self protection project) [1]

[1] https://github.com/KSPP/linux/issues/88

>
> ...
>
> >                 case -1:
> >                         i++;
> >                         /* make debug message */
> > -                       strcpy(msg, "");
> > +                       msg[0] =3D 0;
>
> Strictly speaking it should be '\0'.

Ok, understood.

>
> >                         j =3D i + 1;
> >                         while (par->init_sequence[j] >=3D 0) {
> >                                 sprintf(str, "0x%02X ", par->init_sequ=
ence[j]);
>
>
> --
> With Best Regards,
> Andy Shevchenko

Thanks for the feedback,
Len