Merge tag 'nf-23-06-27' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf

Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains Netfilter fixes for net:

1) Reset shift on Boyer-Moore string match for each block,
   from Jeremy Sowden.

2) Fix acccess to non-linear area in DCCP conntrack helper,
   from Florian Westphal.

3) Fix kernel-doc warnings, by Randy Dunlap.

4) Bail out if expires= does not show in SIP helper message,
   or make ct_sip_parse_numerical_param() tristate and report
   error if expires= cannot be parsed.

5) Unbind non-anonymous set in case rule construction fails.

6) Fix underflow in chain reference counter in case set element
   already exists or it cannot be created.

netfilter pull request 23-06-27

====================

Link: https://lore.kernel.org/r/20230627065304.66394-1-pablo@netfilter.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Author: Paolo Abeni

include/linux/netfilter.h

@@ -481,7 +481,7 @@ struct nfnl_ct_hook {
 };
 extern const struct nfnl_ct_hook __rcu *nfnl_ct_hook;
 
-/**
+/*
  * nf_skb_duplicated - TEE target has sent a packet
  *
  * When a xtables target sends a packet, the OUTPUT and POSTROUTING
@@ -492,7 +492,7 @@ extern const struct nfnl_ct_hook __rcu *nfnl_ct_hook;
  */
 DECLARE_PER_CPU(bool, nf_skb_duplicated);
 
-/**
+/*
  * Contains bitmask of ctnetlink event subscribers, if any.
  * Can't be pernet due to NETLINK_LISTEN_ALL_NSID setsockopt flag.
  */

lib/ts_bm.c

@@ -60,10 +60,12 @@ static unsigned int bm_find(struct ts_config *conf, struct ts_state *state)
 	struct ts_bm *bm = ts_config_priv(conf);
 	unsigned int i, text_len, consumed = state->offset;
 	const u8 *text;
-	int shift = bm->patlen - 1, bs;
+	int bs;
 	const u8 icase = conf->flags & TS_IGNORECASE;
 
 	for (;;) {
+		int shift = bm->patlen - 1;
+
 		text_len = conf->get_next_block(consumed, &text, conf, state);
 
 		if (unlikely(text_len == 0))

net/netfilter/nf_conntrack_proto_dccp.c

@@ -432,9 +432,19 @@ static bool dccp_error(const struct dccp_hdr *dh,
 		       struct sk_buff *skb, unsigned int dataoff,
 		       const struct nf_hook_state *state)
 {
+	static const unsigned long require_seq48 = 1 << DCCP_PKT_REQUEST |
+						   1 << DCCP_PKT_RESPONSE |
+						   1 << DCCP_PKT_CLOSEREQ |
+						   1 << DCCP_PKT_CLOSE |
+						   1 << DCCP_PKT_RESET |
+						   1 << DCCP_PKT_SYNC |
+						   1 << DCCP_PKT_SYNCACK;
 	unsigned int dccp_len = skb->len - dataoff;
 	unsigned int cscov;
 	const char *msg;
+	u8 type;
+
+	BUILD_BUG_ON(DCCP_PKT_INVALID >= BITS_PER_LONG);
 
 	if (dh->dccph_doff * 4 < sizeof(struct dccp_hdr) ||
 	    dh->dccph_doff * 4 > dccp_len) {
@@ -459,34 +469,70 @@ static bool dccp_error(const struct dccp_hdr *dh,
 		goto out_invalid;
 	}
 
-	if (dh->dccph_type >= DCCP_PKT_INVALID) {
+	type = dh->dccph_type;
+	if (type >= DCCP_PKT_INVALID) {
 		msg = "nf_ct_dccp: reserved packet type ";
 		goto out_invalid;
 	}
+
+	if (test_bit(type, &require_seq48) && !dh->dccph_x) {
+		msg = "nf_ct_dccp: type lacks 48bit sequence numbers";
+		goto out_invalid;
+	}
+
 	return false;
 out_invalid:
 	nf_l4proto_log_invalid(skb, state, IPPROTO_DCCP, "%s", msg);
 	return true;
 }
 
+struct nf_conntrack_dccp_buf {
+	struct dccp_hdr dh;	 /* generic header part */
+	struct dccp_hdr_ext ext; /* optional depending dh->dccph_x */
+	union {			 /* depends on header type */
+		struct dccp_hdr_ack_bits ack;
+		struct dccp_hdr_request req;
+		struct dccp_hdr_response response;
+		struct dccp_hdr_reset rst;
+	} u;
+};
+
+static struct dccp_hdr *
+dccp_header_pointer(const struct sk_buff *skb, int offset, const struct dccp_hdr *dh,
+		    struct nf_conntrack_dccp_buf *buf)
+{
+	unsigned int hdrlen = __dccp_hdr_len(dh);
+
+	if (hdrlen > sizeof(*buf))
+		return NULL;
+
+	return skb_header_pointer(skb, offset, hdrlen, buf);
+}
+
 int nf_conntrack_dccp_packet(struct nf_conn *ct, struct sk_buff *skb,
 			     unsigned int dataoff,
 			     enum ip_conntrack_info ctinfo,
 			     const struct nf_hook_state *state)
 {
 	enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
-	struct dccp_hdr _dh, *dh;
+	struct nf_conntrack_dccp_buf _dh;
 	u_int8_t type, old_state, new_state;
 	enum ct_dccp_roles role;
 	unsigned int *timeouts;
+	struct dccp_hdr *dh;
 
-	dh = skb_header_pointer(skb, dataoff, sizeof(_dh), &_dh);
+	dh = skb_header_pointer(skb, dataoff, sizeof(*dh), &_dh.dh);
 	if (!dh)
 		return NF_DROP;
 
 	if (dccp_error(dh, skb, dataoff, state))
 		return -NF_ACCEPT;
 
+	/* pull again, including possible 48 bit sequences and subtype header */
+	dh = dccp_header_pointer(skb, dataoff, dh, &_dh);
+	if (!dh)
+		return NF_DROP;
+
 	type = dh->dccph_type;
 	if (!nf_ct_is_confirmed(ct) && !dccp_new(ct, skb, dh, state))
 		return -NF_ACCEPT;

net/netfilter/nf_conntrack_sip.c

@@ -611,7 +611,7 @@ int ct_sip_parse_numerical_param(const struct nf_conn *ct, const char *dptr,
 	start += strlen(name);
 	*val = simple_strtoul(start, &end, 0);
 	if (start == end)
-		return 0;
+		return -1;
 	if (matchoff && matchlen) {
 		*matchoff = start - dptr;
 		*matchlen = end - start;

net/netfilter/nf_tables_api.c

@@ -5343,6 +5343,8 @@ void nf_tables_deactivate_set(const struct nft_ctx *ctx, struct nft_set *set,
 		nft_set_trans_unbind(ctx, set);
 		if (nft_set_is_anonymous(set))
 			nft_deactivate_next(ctx->net, set);
+		else
+			list_del_rcu(&binding->list);
 
 		set->use--;
 		break;
@@ -6769,7 +6771,9 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
 err_element_clash:
 	kfree(trans);
 err_elem_free:
-	nft_set_elem_destroy(set, elem.priv, true);
+	nf_tables_set_elem_destroy(ctx, set, elem.priv);
+	if (obj)
+		obj->use--;
 err_parse_data:
 	if (nla[NFTA_SET_ELEM_DATA] != NULL)
 		nft_data_release(&elem.data.val, desc.type);