netfilter: nf_tables: add rescheduling points during loop detection walks

[ Upstream commit 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>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 3ad2b22886ff06934ce90fa0b51a8118a78e1373..361fbbd430ad87fcf9d9d09f3eb1e31a263b37fe 100644 (file)
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -3442,6 +3442,8 @@ int nft_chain_validate(const struct nft_ctx *ctx, const struct nft_chain *chain)
                        if (err < 0)
                                return err;
                }
+
+               cond_resched();
        }
 
        return 0;
@@ -10041,9 +10043,13 @@ 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))
                        continue;
                if (!(set->flags & NFT_SET_MAP) ||