Re: [PATCH -stable,5.10 02/10] netfilter: nf_tables: add rescheduling points during loop detection walks

Pablo Neira Ayuso
2023-07-05T14:33:41Z

On Wed, Jul 05, 2023 at 04:31:07PM +0200, Florian Westphal wrote:
> Pablo Neira Ayuso <pablo@netfilter.org> wrote:
> > From: Florian Westphal <fw@strlen.de>
> >
> > [ 81ea010667417ef3f218dfd99b69769fe66c2b67 ]
> >
> > Add explicit rescheduling points during ruleset walk.
> >
> > Switching to a faster algorithm is possible but this is a much
> > smaller change, suitable for nf tree.
> >
> > Link: https://bugzilla.netfilter.org/show_bug.cgi?id=1460
> > Signed-off-by: Florian Westphal <fw@strlen.de>
> > Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
> > ---
> > net/netfilter/nf_tables_api.c | 6 ++++++
> > 1 file changed, 6 insertions(+)
> >
> > diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
> > index e3865f29ae83..3c9292d3f826 100644
> > --- a/net/netfilter/nf_tables_api.c
> > +++ b/net/netfilter/nf_tables_api.c
> > @@ -3164,6 +3164,8 @@ int nft_chain_validate(const struct nft_ctx *ctx, const struct nft_chain *chain)
> > if (err < 0)
> > return err;
> > }
> > +
> > + cond_resched();
> > }
> >
> > return 0;
> > @@ -8506,9 +8508,13 @@ static int nf_tables_check_loops(const struct nft_ctx *ctx,
> > break;
> > }
> > }
> > +
> > + cond_resched();
> > }
> >
> > list_for_each_entry(set, &ctx->table->sets, list) {
> > + cond_resched();
> > +
> > if (!nft_is_active_next(ctx->net, set))
>
> Nack, this is wrong. Either drop this patch or also pick up
> 2024439bd5ceb145eeeb428b2a59e9b905153ac3
> ("netfilter: nf_tables: fix scheduling-while-atomic splat")
> I suspect it will cherry-pick without problems.

OK, I'll respin and send v2.