Merge tag 'nf-25-10-29' of https://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf

Florian Westphal says:

====================
netfilter: updates for net

1) its not possible to attach conntrack labels via ctnetlink
unless one creates a dummy 'ct labels set' rule in nftables.
This is an oversight, the 'ruleset tests presence, userspace
(netlink) sets' use-case is valid and should 'just work'.
Always broken since this got added in Linux 4.7.

2) nft_connlimit reads count value without holding the relevant
lock, add a READ_ONCE annotation. From Fernando Fernandez Mancera.

3) There is a long-standing bug (since 4.12) in nftables helper infra
when NAT is in use: if the helper gets assigned after the nat binding
was set up, we fail to initialise the 'seqadj' extension, which is
needed in case NAT payload rewrites need to add (or remove) from the
packet payload. Fix from Andrii Melnychenko.

* tag 'nf-25-10-29' of https://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
netfilter: nft_ct: add seqadj extension for natted connections
netfilter: nft_connlimit: fix possible data race on connection count
netfilter: nft_ct: enable labels for get case too
====================

Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

net/netfilter/nft_connlimit.c

···
 		return;
 	}
 
-	count = priv->list->count;
+	count = READ_ONCE(priv->list->count);
 
 	if ((count > priv->limit) ^ priv->invert) {
 		regs->verdict.code = NFT_BREAK;

net/netfilter/nft_ct.c

···
 #include <net/netfilter/nf_conntrack_timeout.h>
 #include <net/netfilter/nf_conntrack_l4proto.h>
 #include <net/netfilter/nf_conntrack_expect.h>
+#include <net/netfilter/nf_conntrack_seqadj.h>
 
 struct nft_ct_helper_obj  {
 	struct nf_conntrack_helper *helper4;
···
 }
 #endif
 
+static void __nft_ct_get_destroy(const struct nft_ctx *ctx, struct nft_ct *priv)
+{
+#ifdef CONFIG_NF_CONNTRACK_LABELS
+	if (priv->key == NFT_CT_LABELS)
+		nf_connlabels_put(ctx->net);
+#endif
+}
+
 static int nft_ct_get_init(const struct nft_ctx *ctx,
 			   const struct nft_expr *expr,
 			   const struct nlattr * const tb[])
···
 		if (tb[NFTA_CT_DIRECTION] != NULL)
 			return -EINVAL;
 		len = NF_CT_LABELS_MAX_SIZE;
+
+		err = nf_connlabels_get(ctx->net, (len * BITS_PER_BYTE) - 1);
+		if (err)
+			return err;
 		break;
 #endif
 	case NFT_CT_HELPER:
···
 		case IP_CT_DIR_REPLY:
 			break;
 		default:
-			return -EINVAL;
+			err = -EINVAL;
+			goto err;
 		}
 	}
 
···
 	err = nft_parse_register_store(ctx, tb[NFTA_CT_DREG], &priv->dreg, NULL,
 				       NFT_DATA_VALUE, len);
 	if (err < 0)
-		return err;
+		goto err;
 
 	err = nf_ct_netns_get(ctx->net, ctx->family);
 	if (err < 0)
-		return err;
+		goto err;
 
 	if (priv->key == NFT_CT_BYTES ||
 	    priv->key == NFT_CT_PKTS  ||
···
 		nf_ct_set_acct(ctx->net, true);
 
 	return 0;
+err:
+	__nft_ct_get_destroy(ctx, priv);
+	return err;
 }
 
 static void __nft_ct_set_destroy(const struct nft_ctx *ctx, struct nft_ct *priv)
···
 static void nft_ct_get_destroy(const struct nft_ctx *ctx,
 			       const struct nft_expr *expr)
 {
+	struct nft_ct *priv = nft_expr_priv(expr);
+
+	__nft_ct_get_destroy(ctx, priv);
 	nf_ct_netns_put(ctx->net, ctx->family);
 }
 
···
 	if (help) {
 		rcu_assign_pointer(help->helper, to_assign);
 		set_bit(IPS_HELPER_BIT, &ct->status);
+
+		if ((ct->status & IPS_NAT_MASK) && !nfct_seqadj(ct))
+			if (!nfct_seqadj_ext_add(ct))
+				regs->verdict.code = NF_DROP;
 	}
 }