Merge 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) Harden set element field checks to avoid out-of-bound memory access,
   this patch also fixes the type of issue described in 7e6bc1f6cabc
   ("netfilter: nf_tables: stricter validation of element data") in a
   broader way.

2) Patches to restrict the chain, set, and rule id lookup in the
   transaction to the corresponding top-level table, patches from
   Thadeu Lima de Souza Cascardo.

3) Fix incorrect comment in ip6t_LOG.h

4) nft_data_init() performs upfront validation of the expected data.
   struct nft_data_desc is used to describe the expected data to be
   received from userspace. The .size field represents the maximum size
   that can be stored, for bound checks. Then, .len is an input/output field
   which stores the expected length as input (this is optional, to restrict
   the checks), as output it stores the real length received from userspace
   (if it was not specified as input). This patch comes in response to
   7e6bc1f6cabc ("netfilter: nf_tables: stricter validation of element data")
   to address this type of issue in a more generic way by avoid opencoded
   data validation. Next patch requires this as a dependency.

5) Disallow jump to implicit chain from set element, this configuration
   is invalid. Only allow jump to chain via immediate expression is
   supported at this stage.

6) Fix possible null-pointer derefence in the error path of table updates,
   if memory allocation of the transaction fails. From Florian Westphal.

* git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  netfilter: nf_tables: fix null deref due to zeroed list head
  netfilter: nf_tables: disallow jump to implicit chain from set element
  netfilter: nf_tables: upfront validation of data via nft_data_init()
  netfilter: ip6t_LOG: Fix a typo in a comment
  netfilter: nf_tables: do not allow RULE_ID to refer to another chain
  netfilter: nf_tables: do not allow CHAIN_ID to refer to another table
  netfilter: nf_tables: do not allow SET_ID to refer to another table
  netfilter: nf_tables: validate variable length element extension
====================

Link: https://lore.kernel.org/r/20220809220532.130240-1-pablo@netfilter.org/
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 10 insertions, 3 deletions

diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h
index 8bfb9c74afbf..99aae36c04b9 100644
--- a/include/net/netfilter/nf_tables.h
+++ b/include/net/netfilter/nf_tables.h
@@ -221,13 +221,18 @@ struct nft_ctx {
 	bool				report;
 };
 
+enum nft_data_desc_flags {
+	NFT_DATA_DESC_SETELEM	= (1 << 0),
+};
+
 struct nft_data_desc {
 	enum nft_data_types		type;
+	unsigned int			size;
 	unsigned int			len;
+	unsigned int			flags;
 };
 
-int nft_data_init(const struct nft_ctx *ctx,
-		  struct nft_data *data, unsigned int size,
+int nft_data_init(const struct nft_ctx *ctx, struct nft_data *data,
 		  struct nft_data_desc *desc, const struct nlattr *nla);
 void nft_data_hold(const struct nft_data *data, enum nft_data_types type);
 void nft_data_release(const struct nft_data *data, enum nft_data_types type);
@@ -651,6 +656,7 @@ extern const struct nft_set_ext_type nft_set_ext_types[];
 struct nft_set_ext_tmpl {
 	u16	len;
 	u8	offset[NFT_SET_EXT_NUM];
+	u8	ext_len[NFT_SET_EXT_NUM];
 };
 
 /**
@@ -680,7 +686,8 @@ static inline int nft_set_ext_add_length(struct nft_set_ext_tmpl *tmpl, u8 id,
 		return -EINVAL;
 
 	tmpl->offset[id] = tmpl->len;
-	tmpl->len	+= nft_set_ext_types[id].len + len;
+	tmpl->ext_len[id] = nft_set_ext_types[id].len + len;
+	tmpl->len	+= tmpl->ext_len[id];
 
 	return 0;
 }