netfilter: nf_tables: add rescheduling points during loop detection walks

Florian Westphal · gregkh · commit 077ef851f0a3 · 2023-07-27T08:37:27.000+02:00
[ 81ea010 ] 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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
@@ -2712,6 +2712,8 @@ int nft_chain_validate(const struct nft_ctx *ctx, const struct nft_chain *chain)
 			if (err < 0)
 				return err;
 		}
+
+		cond_resched();
 	}
 
 	return 0;
@@ -7379,9 +7381,13 @@ 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) ||

Original file line number	Diff line number	Diff line change
`@@ -2712,6 +2712,8 @@ int nft_chain_validate(const struct nft_ctx ctx, const struct nft_chain chain)`
`2712`	`2712`	`if (err < 0)`
`2713`	`2713`	`return err;`
`2714`	`2714`	`}`
	`2715`	`+`
	`2716`	`+ cond_resched();`
`2715`	`2717`	`}`
`2716`	`2718`
`2717`	`2719`	`return 0;`
`@@ -7379,9 +7381,13 @@ static int nf_tables_check_loops(const struct nft_ctx *ctx,`
`7379`	`7381`	`break;`
`7380`	`7382`	`}`
`7381`	`7383`	`}`
	`7384`	`+`
	`7385`	`+ cond_resched();`
`7382`	`7386`	`}`
`7383`	`7387`
`7384`	`7388`	`list_for_each_entry(set, &ctx->table->sets, list) {`
	`7389`	`+ cond_resched();`
	`7390`	`+`
`7385`	`7391`	`if (!nft_is_active_next(ctx->net, set))`
`7386`	`7392`	`continue;`
`7387`	`7393`	`if (!(set->flags & NFT_SET_MAP) \|\|`