Merge tag 'nf-23-08-31' 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) Fix mangling of TCP options with non-linear skbuff, from Xiao Liang.

2) OOB read in xt_sctp due to missing sanitization of array length field.
   From Wander Lairson Costa.

3) OOB read in xt_u32 due to missing sanitization of array length field.
   Also from Wander Lairson Costa.

All of them above, always broken for several releases.

4) Missing audit log for set element reset command, from Phil Sutter.

5) Missing audit log for rule reset command, also from Phil.

These audit log support are missing in 6.5.

* tag 'nf-23-08-31' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  netfilter: nf_tables: Audit log rule reset
  netfilter: nf_tables: Audit log setelem reset
  netfilter: xt_u32: validate user space input
  netfilter: xt_sctp: validate the flag_info count
  netfilter: nft_exthdr: Fix non-linear header modification
====================

Link: https://lore.kernel.org/r/20230830235935.465690-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

4 files changed, 77 insertions, 15 deletions

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 41b826dff6f5..2c81cee858d6 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -102,6 +102,7 @@ static const u8 nft2audit_op[NFT_MSG_MAX] = { // enum nf_tables_msg_types
 	[NFT_MSG_NEWFLOWTABLE]	= AUDIT_NFT_OP_FLOWTABLE_REGISTER,
 	[NFT_MSG_GETFLOWTABLE]	= AUDIT_NFT_OP_INVALID,
 	[NFT_MSG_DELFLOWTABLE]	= AUDIT_NFT_OP_FLOWTABLE_UNREGISTER,
+	[NFT_MSG_GETSETELEM_RESET] = AUDIT_NFT_OP_SETELEM_RESET,
 };
 
 static void nft_validate_state_update(struct nft_table *table, u8 new_validate_state)
@@ -3421,6 +3422,18 @@ err:
 	nfnetlink_set_err(ctx->net, ctx->portid, NFNLGRP_NFTABLES, -ENOBUFS);
 }
 
+static void audit_log_rule_reset(const struct nft_table *table,
+				 unsigned int base_seq,
+				 unsigned int nentries)
+{
+	char *buf = kasprintf(GFP_ATOMIC, "%s:%u",
+			      table->name, base_seq);
+
+	audit_log_nfcfg(buf, table->family, nentries,
+			AUDIT_NFT_OP_RULE_RESET, GFP_ATOMIC);
+	kfree(buf);
+}
+
 struct nft_rule_dump_ctx {
 	char *table;
 	char *chain;
@@ -3527,6 +3540,9 @@ static int nf_tables_dump_rules(struct sk_buff *skb,
 done:
 	rcu_read_unlock();
 
+	if (reset && idx > cb->args[0])
+		audit_log_rule_reset(table, cb->seq, idx - cb->args[0]);
+
 	cb->args[0] = idx;
 	return skb->len;
 }
@@ -3634,6 +3650,9 @@ static int nf_tables_getrule(struct sk_buff *skb, const struct nfnl_info *info,
 	if (err < 0)
 		goto err_fill_rule_info;
 
+	if (reset)
+		audit_log_rule_reset(table, nft_pernet(net)->base_seq, 1);
+
 	return nfnetlink_unicast(skb2, net, NETLINK_CB(skb).portid);
 
 err_fill_rule_info:
@@ -5624,13 +5643,25 @@ static int nf_tables_dump_setelem(const struct nft_ctx *ctx,
 	return nf_tables_fill_setelem(args->skb, set, elem, args->reset);
 }
 
+static void audit_log_nft_set_reset(const struct nft_table *table,
+				    unsigned int base_seq,
+				    unsigned int nentries)
+{
+	char *buf = kasprintf(GFP_ATOMIC, "%s:%u", table->name, base_seq);
+
+	audit_log_nfcfg(buf, table->family, nentries,
+			AUDIT_NFT_OP_SETELEM_RESET, GFP_ATOMIC);
+	kfree(buf);
+}
+
 struct nft_set_dump_ctx {
 	const struct nft_set	*set;
 	struct nft_ctx		ctx;
 };
 
 static int nft_set_catchall_dump(struct net *net, struct sk_buff *skb,
-				 const struct nft_set *set, bool reset)
+				 const struct nft_set *set, bool reset,
+				 unsigned int base_seq)
 {
 	struct nft_set_elem_catchall *catchall;
 	u8 genmask = nft_genmask_cur(net);
@@ -5646,6 +5677,8 @@ static int nft_set_catchall_dump(struct net *net, struct sk_buff *skb,
 
 		elem.priv = catchall->elem;
 		ret = nf_tables_fill_setelem(skb, set, &elem, reset);
+		if (reset && !ret)
+			audit_log_nft_set_reset(set->table, base_seq, 1);
 		break;
 	}
 
@@ -5725,12 +5758,17 @@ static int nf_tables_dump_set(struct sk_buff *skb, struct netlink_callback *cb)
 	set->ops->walk(&dump_ctx->ctx, set, &args.iter);
 
 	if (!args.iter.err && args.iter.count == cb->args[0])
-		args.iter.err = nft_set_catchall_dump(net, skb, set, reset);
+		args.iter.err = nft_set_catchall_dump(net, skb, set,
+						      reset, cb->seq);
 	rcu_read_unlock();
 
 	nla_nest_end(skb, nest);
 	nlmsg_end(skb, nlh);
 
+	if (reset && args.iter.count > args.iter.skip)
+		audit_log_nft_set_reset(table, cb->seq,
+					args.iter.count - args.iter.skip);
+
 	if (args.iter.err && args.iter.err != -EMSGSIZE)
 		return args.iter.err;
 	if (args.iter.count == cb->args[0])
@@ -5955,13 +5993,13 @@ static int nf_tables_getsetelem(struct sk_buff *skb,
 	struct netlink_ext_ack *extack = info->extack;
 	u8 genmask = nft_genmask_cur(info->net);
 	u8 family = info->nfmsg->nfgen_family;
+	int rem, err = 0, nelems = 0;
 	struct net *net = info->net;
 	struct nft_table *table;
 	struct nft_set *set;
 	struct nlattr *attr;
 	struct nft_ctx ctx;
 	bool reset = false;
-	int rem, err = 0;
 
 	table = nft_table_lookup(net, nla[NFTA_SET_ELEM_LIST_TABLE], family,
 				 genmask, 0);
@@ -6004,8 +6042,13 @@ static int nf_tables_getsetelem(struct sk_buff *skb,
 			NL_SET_BAD_ATTR(extack, attr);
 			break;
 		}
+		nelems++;
 	}
 
+	if (reset)
+		audit_log_nft_set_reset(table, nft_pernet(net)->base_seq,
+					nelems);
+
 	return err;
 }
 
diff --git a/net/netfilter/nft_exthdr.c b/net/netfilter/nft_exthdr.c
index 7f856ceb3a66..a9844eefedeb 100644
--- a/net/netfilter/nft_exthdr.c
+++ b/net/netfilter/nft_exthdr.c
@@ -238,7 +238,12 @@ static void nft_exthdr_tcp_set_eval(const struct nft_expr *expr,
 	if (!tcph)
 		goto err;
 
+	if (skb_ensure_writable(pkt->skb, nft_thoff(pkt) + tcphdr_len))
+		goto err;
+
+	tcph = (struct tcphdr *)(pkt->skb->data + nft_thoff(pkt));
 	opt = (u8 *)tcph;
+
 	for (i = sizeof(*tcph); i < tcphdr_len - 1; i += optl) {
 		union {
 			__be16 v16;
@@ -253,15 +258,6 @@ static void nft_exthdr_tcp_set_eval(const struct nft_expr *expr,
 		if (i + optl > tcphdr_len || priv->len + priv->offset > optl)
 			goto err;
 
-		if (skb_ensure_writable(pkt->skb,
-					nft_thoff(pkt) + i + priv->len))
-			goto err;
-
-		tcph = nft_tcp_header_pointer(pkt, sizeof(buff), buff,
-					      &tcphdr_len);
-		if (!tcph)
-			goto err;
-
 		offset = i + priv->offset;
 
 		switch (priv->len) {
@@ -325,9 +321,9 @@ static void nft_exthdr_tcp_strip_eval(const struct nft_expr *expr,
 	if (skb_ensure_writable(pkt->skb, nft_thoff(pkt) + tcphdr_len))
 		goto drop;
 
-	opt = (u8 *)nft_tcp_header_pointer(pkt, sizeof(buff), buff, &tcphdr_len);
-	if (!opt)
-		goto err;
+	tcph = (struct tcphdr *)(pkt->skb->data + nft_thoff(pkt));
+	opt = (u8 *)tcph;
+
 	for (i = sizeof(*tcph); i < tcphdr_len - 1; i += optl) {
 		unsigned int j;
 
diff --git a/net/netfilter/xt_sctp.c b/net/netfilter/xt_sctp.c
index e8961094a282..b46a6a512058 100644
--- a/net/netfilter/xt_sctp.c
+++ b/net/netfilter/xt_sctp.c
@@ -149,6 +149,8 @@ static int sctp_mt_check(const struct xt_mtchk_param *par)
 {
 	const struct xt_sctp_info *info = par->matchinfo;
 
+	if (info->flag_count > ARRAY_SIZE(info->flag_info))
+		return -EINVAL;
 	if (info->flags & ~XT_SCTP_VALID_FLAGS)
 		return -EINVAL;
 	if (info->invflags & ~XT_SCTP_VALID_FLAGS)
diff --git a/net/netfilter/xt_u32.c b/net/netfilter/xt_u32.c
index 177b40d08098..117d4615d668 100644
--- a/net/netfilter/xt_u32.c
+++ b/net/netfilter/xt_u32.c
@@ -96,11 +96,32 @@ static bool u32_mt(const struct sk_buff *skb, struct xt_action_param *par)
 	return ret ^ data->invert;
 }
 
+static int u32_mt_checkentry(const struct xt_mtchk_param *par)
+{
+	const struct xt_u32 *data = par->matchinfo;
+	const struct xt_u32_test *ct;
+	unsigned int i;
+
+	if (data->ntests > ARRAY_SIZE(data->tests))
+		return -EINVAL;
+
+	for (i = 0; i < data->ntests; ++i) {
+		ct = &data->tests[i];
+
+		if (ct->nnums > ARRAY_SIZE(ct->location) ||
+		    ct->nvalues > ARRAY_SIZE(ct->value))
+			return -EINVAL;
+	}
+
+	return 0;
+}
+
 static struct xt_match xt_u32_mt_reg __read_mostly = {
 	.name       = "u32",
 	.revision   = 0,
 	.family     = NFPROTO_UNSPEC,
 	.match      = u32_mt,
+	.checkentry = u32_mt_checkentry,
 	.matchsize  = sizeof(struct xt_u32),
 	.me         = THIS_MODULE,
 };