Re: [syzbot] [bpf?] general protection fault in bpf_prog_offload_verifier_prep

From: Stanislav Fomichev
Date: Wed Sep 06 2023 - 14:37:27 EST


On 09/06, Eduard Zingerman wrote:
> On Wed, 2023-09-06 at 07:57 -0700, Jakub Kicinski wrote:
> > On Wed, 06 Sep 2023 16:50:23 +0300 Eduard Zingerman wrote:
> > > diff --git a/kernel/bpf/offload.c b/kernel/bpf/offload.c
> > > index 3e4f2ec1af06..302e38bffffa 100644
> > > --- a/kernel/bpf/offload.c
> > > +++ b/kernel/bpf/offload.c
> > > @@ -199,12 +199,11 @@ static int __bpf_prog_dev_bound_init(struct bpf_prog *prog, struct net_device *n
> > > offload->netdev = netdev;
> > >
> > > ondev = bpf_offload_find_netdev(offload->netdev);
> > > + if (bpf_prog_is_offloaded(prog->aux) && (!ondev || !ondev->offdev)) {
> > > + err = -EINVAL;
> > > + goto err_free;
> > > + }
> > > if (!ondev) {
> > > - if (bpf_prog_is_offloaded(prog->aux)) {
> > > - err = -EINVAL;
> > > - goto err_free;
> > > - }
> > > -
> > > /* When only binding to the device, explicitly
> > > * create an entry in the hashtable.
> > > */
> >
> > LGTM, FWIW.
>
> Thanks, I'll wrap it up as a proper patch with a test.

LGTM as well, thanks!