Re: [PATCH] ARM: kprobes: Avoid fortify_panic() when copying optprobe template

Andrew Jeffery
2020-05-18T00:50:17Z

On Mon, 18 May 2020, at 07:18, Kees Cook wrote:
> On Mon, May 18, 2020 at 01:09:59AM +0930, Andrew Jeffery wrote:
> > As mentioned, a couple of attempts have been made to address the issue
> > by casting a pointer to optprobe_template_entry before providing it to
> > memcpy(), however gccs such as Ubuntu 20.04's arm-linux-gnueabi-gcc
> > 9.3.0 (Ubuntu 9.3.0-10ubuntu1) see through these efforts.
>
> Ah, dang. :P
>
> How about converting them all to unsized arrays, which would also allow
> the code to drop the "&" everywhere, I think. This is untested:

Looks better than my hack. Took it for a spin under qemu and it works for me.

Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
Tested-by: Andrew Jeffery <andrew@aj.id.au>

Thanks Kees!

Andrew