Re: [PATCH net-next] ptr_ring: fix integer overflow

[Jason Wang]

On 2018å01æ30æ 01:01, David Miller wrote:
> From: Jason Wang <jasowang@xxxxxxxxxx>
> Date: Thu, 25 Jan 2018 15:31:42 +0800
>
> > We try to allocate one more entry for lockless peeking. The adding
> > operation may overflow which causes zero to be passed to kmalloc().
> > In this case, it returns ZERO_SIZE_PTR without any notice by ptr
> > ring. Try to do producing or consuming on such ring will lead NULL
> > dereference. Fix this detect and fail early.
> >
> > Fixes: bcecb4bbf88a ("net: ptr_ring: otherwise safe empty checks can overrun array bounds")
> > Reported-by: syzbot+87678bcf753b44c39b67@xxxxxxxxxxxxxxxxxxxxxxxxx
> > Cc: John Fastabend <john.fastabend@xxxxxxxxx>
> > Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
> I'm dropping this because I am to understand that Michael Tsirkin's patch
> series covers this issue.

Yes.

> Let me know if I still need to apply this.
>
> Thanks.

No need for this.

Thanks