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From:   Andy Shevchenko <andy.shevchenko@gmail.com>
Date:   Sun, 18 Jul 2021 22:42:42 +0300
Message-ID: <CAHp75VeEA0=KFsfdjCnBm-b9+F+NnFWJ38nkh+qtb85XdXVWog@mail.gmail.com>
Subject: Re: [PATCH] staging/fbtft: Remove all strcpy() uses
To:     Len Baker <len.baker@gmx.com>
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        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>
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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 want
> 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?

...

>                 case -1:
>                         i++;
>                         /* make debug message */
> -                       strcpy(msg, "");
> +                       msg[0] = 0;

Strictly speaking it should be '\0'.

>                         j = i + 1;
>                         while (par->init_sequence[j] >= 0) {
>                                 sprintf(str, "0x%02X ", par->init_sequence[j]);


-- 
With Best Regards,
Andy Shevchenko