Re: [PATCH bpf 1/4] bpf_trace: check size for overflow in bpf_kprobe_multi_link_attach

[Alexei Starovoitov]

On Tue, May 17, 2022 at 12:49:34AM +0200, Eugene Syromiatnikov wrote:
> On Mon, May 16, 2022 at 11:34:45PM +0200, Jiri Olsa wrote:
> > On Mon, May 16, 2022 at 08:27:08PM +0200, Eugene Syromiatnikov wrote:
> > > +	if (check_mul_overflow(cnt, sizeof(*syms), &size))
> > > +		return -EOVERFLOW;
> > 
> > there was an update already:
> > 
> >   0236fec57a15 bpf: Resolve symbols with ftrace_lookup_symbols for kprobe multi link
> > 
> > so this won't apply anymore, could you please rebase on top of the latest bpf-next/master?
> 
> The issue that this specific check has to go in 4.18, as it covers
> possible out-of-bounds write, I'm not sure how to handle it, have
> a branch where it is merged manually?

As Jiri said, please use bpf-next.