Re: [PATCH] kretprobe: check re-registration of the same kretprobe earlier

[chengjian (D)]

On 2020/3/7 17:54, Masami Hiramatsu wrote:
> Ah, I see. I thought that you said ri is use-after-free, but in reality,
> rp is use-after-free (use-after-init). OK.
>
> > And the problem here is destructive, it destroyed all the data of the
> > previously registered kretprobe,
> > it can lead to a system crash, memory leak, use-after-free and even some
> > other unexpected behavior.
> Yes, so I think we should do
>
> +	/* Return error if it's being re-registered */
> +	ret = check_kprobe_rereg(&rp->kp);
> +	if (WARN_ON(ret))
> +		return ret;
>
> This will give a warning message to the developer.
>
> Thank you,

OK, I will add the WARN_ON in V2.

Thank you.


----Cheng Jian