Re: [PATCH] printk: fix buffer overflow potential for print_text()

[John Ogness]

Hi Sven,

Thanks for the outstanding analysis!

On 2021-01-23, Sven Schnelle <svens@xxxxxxxxxxxxx> wrote:
>> 1401		if (buf_size > 0)
>> 1402			text[len] = 0;
>
> I don't think i have really understood how all the printk magic works,
> but using r->text_buf[len] seems to be the correct place to put the
> zero byte in that case?

Yes, you are correct! @text is pointing to the beginning of the
currently processed line, not the beginning of the buffer.

I will submit a patch to fix our recent fix (unless you would like to do
that).

Thank you for all your help with this!

John Ogness