On 02/17, Yafang Shao wrote:
>
> On Sat, Feb 17, 2024 at 8:05 PM Oleg Nesterov <oleg@xxxxxxxxxx> wrote:
> >
> > > Fixes: ac8148d957f5 ("bpf: bpf_iter_task_next: use next_task(kit->task) rather than next_task(kit->pos)")
> >
> > Confused...
> >
> > Does this mean that bpf_iter_task_next() (the only user of ->pos) can be
> > called even if bpf_iter_task_new() returns -EINVAL ?
>
> Right. The bpf_for_each() doesn't check the return value of bpf_iter_task_new
> (), see also https://lore.kernel.org/bpf/20240208090906.56337-4-laoar.shao@xxxxxxxxx/
>
> Even if we check the return value of bpf_iter_task_new() in
> bpf_for_each(), we still need to fix it in the kernel.
Hmm, OK. Somehow I naively thought there must be an in-kernel check that
would that prevent bpf_iter_task_next() if bpf_iter_task_new() failed.
Thanks for your explanations. FWIW,
Acked-by: Oleg Nesterov <oleg@xxxxxxxxxx>
