[net,2/3] netfilter: nf_tables: add rescheduling points during loop detection walks

Commit Message

Florian Westphal July 26, 2022, 7:20 p.m. UTC

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 <[e-mail]>
Acked-by: Pablo Neira Ayuso <[e-mail]>
---
 net/netfilter/nf_tables_api.c | 6 ++++++
 1 file changed, 6 insertions(+)

Patch

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 646d5fd53604..9f976b11d896 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -3340,6 +3340,8 @@  int nft_chain_validate(const struct nft_ctx *ctx, const struct nft_chain *chain)
 			if (err < 0)
 				return err;
 		}
+
+		cond_resched();
 	}
 
 	return 0;
@@ -9367,9 +9369,13 @@  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) ||