From 34aae2c2fb1e3d88a5aeee16715cb6bf0336cdce Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Tue, 9 Aug 2022 11:25:43 +0200 Subject: [PATCH 1/8] netfilter: nf_tables: validate variable length element extension Update template to validate variable length extensions. This patch adds a new .ext_len[id] field to the template to store the expected extension length. This is used to sanity check the initialization of the variable length extension. Use PTR_ERR() in nft_set_elem_init() to report errors since, after this update, there are two reason why this might fail, either because of ENOMEM or insufficient room in the extension field (EINVAL). Kernels up until 7e6bc1f6cabc ("netfilter: nf_tables: stricter validation of element data") allowed to copy more data to the extension than was allocated. This ext_len field allows to validate if the destination has the correct size as additional check. Signed-off-by: Pablo Neira Ayuso --- include/net/netfilter/nf_tables.h | 4 +- net/netfilter/nf_tables_api.c | 84 +++++++++++++++++++++++++------ net/netfilter/nft_dynset.c | 2 +- 3 files changed, 73 insertions(+), 17 deletions(-) diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h index 8bfb9c74afbf..7ece4fd0cf66 100644 --- a/include/net/netfilter/nf_tables.h +++ b/include/net/netfilter/nf_tables.h @@ -651,6 +651,7 @@ 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 +681,8 @@ 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; } diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 9f976b11d896..3b09e13b9b5c 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -5467,6 +5467,27 @@ struct nft_expr *nft_set_elem_expr_alloc(const struct nft_ctx *ctx, return ERR_PTR(err); } +static int nft_set_ext_check(const struct nft_set_ext_tmpl *tmpl, u8 id, u32 len) +{ + len += nft_set_ext_types[id].len; + if (len > tmpl->ext_len[id] || + len > U8_MAX) + return -1; + + return 0; +} + +static int nft_set_ext_memcpy(const struct nft_set_ext_tmpl *tmpl, u8 id, + void *to, const void *from, u32 len) +{ + if (nft_set_ext_check(tmpl, id, len) < 0) + return -1; + + memcpy(to, from, len); + + return 0; +} + void *nft_set_elem_init(const struct nft_set *set, const struct nft_set_ext_tmpl *tmpl, const u32 *key, const u32 *key_end, @@ -5477,17 +5498,26 @@ void *nft_set_elem_init(const struct nft_set *set, elem = kzalloc(set->ops->elemsize + tmpl->len, gfp); if (elem == NULL) - return NULL; + return ERR_PTR(-ENOMEM); ext = nft_set_elem_ext(set, elem); nft_set_ext_init(ext, tmpl); - if (nft_set_ext_exists(ext, NFT_SET_EXT_KEY)) - memcpy(nft_set_ext_key(ext), key, set->klen); - if (nft_set_ext_exists(ext, NFT_SET_EXT_KEY_END)) - memcpy(nft_set_ext_key_end(ext), key_end, set->klen); - if (nft_set_ext_exists(ext, NFT_SET_EXT_DATA)) - memcpy(nft_set_ext_data(ext), data, set->dlen); + if (nft_set_ext_exists(ext, NFT_SET_EXT_KEY) && + nft_set_ext_memcpy(tmpl, NFT_SET_EXT_KEY, + nft_set_ext_key(ext), key, set->klen) < 0) + goto err_ext_check; + + if (nft_set_ext_exists(ext, NFT_SET_EXT_KEY_END) && + nft_set_ext_memcpy(tmpl, NFT_SET_EXT_KEY_END, + nft_set_ext_key_end(ext), key_end, set->klen) < 0) + goto err_ext_check; + + if (nft_set_ext_exists(ext, NFT_SET_EXT_DATA) && + nft_set_ext_memcpy(tmpl, NFT_SET_EXT_DATA, + nft_set_ext_data(ext), data, set->dlen) < 0) + goto err_ext_check; + if (nft_set_ext_exists(ext, NFT_SET_EXT_EXPIRATION)) { *nft_set_ext_expiration(ext) = get_jiffies_64() + expiration; if (expiration == 0) @@ -5497,6 +5527,11 @@ void *nft_set_elem_init(const struct nft_set *set, *nft_set_ext_timeout(ext) = timeout; return elem; + +err_ext_check: + kfree(elem); + + return ERR_PTR(-EINVAL); } static void __nft_set_elem_expr_destroy(const struct nft_ctx *ctx, @@ -5584,14 +5619,25 @@ int nft_set_elem_expr_clone(const struct nft_ctx *ctx, struct nft_set *set, } static int nft_set_elem_expr_setup(struct nft_ctx *ctx, + const struct nft_set_ext_tmpl *tmpl, const struct nft_set_ext *ext, struct nft_expr *expr_array[], u32 num_exprs) { struct nft_set_elem_expr *elem_expr = nft_set_ext_expr(ext); + u32 len = sizeof(struct nft_set_elem_expr); struct nft_expr *expr; int i, err; + if (num_exprs == 0) + return 0; + + for (i = 0; i < num_exprs; i++) + len += expr_array[i]->ops->size; + + if (nft_set_ext_check(tmpl, NFT_SET_EXT_EXPRESSIONS, len) < 0) + return -EINVAL; + for (i = 0; i < num_exprs; i++) { expr = nft_setelem_expr_at(elem_expr, elem_expr->size); err = nft_expr_clone(expr, expr_array[i]); @@ -6054,17 +6100,23 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set, } } - err = -ENOMEM; elem.priv = nft_set_elem_init(set, &tmpl, elem.key.val.data, elem.key_end.val.data, elem.data.val.data, timeout, expiration, GFP_KERNEL_ACCOUNT); - if (elem.priv == NULL) + if (IS_ERR(elem.priv)) { + err = PTR_ERR(elem.priv); goto err_parse_data; + } ext = nft_set_elem_ext(set, elem.priv); if (flags) *nft_set_ext_flags(ext) = flags; + if (ulen > 0) { + if (nft_set_ext_check(&tmpl, NFT_SET_EXT_USERDATA, ulen) < 0) { + err = -EINVAL; + goto err_elem_userdata; + } udata = nft_set_ext_userdata(ext); udata->len = ulen - 1; nla_memcpy(&udata->data, nla[NFTA_SET_ELEM_USERDATA], ulen); @@ -6073,14 +6125,14 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set, *nft_set_ext_obj(ext) = obj; obj->use++; } - err = nft_set_elem_expr_setup(ctx, ext, expr_array, num_exprs); + err = nft_set_elem_expr_setup(ctx, &tmpl, ext, expr_array, num_exprs); if (err < 0) - goto err_elem_expr; + goto err_elem_free; trans = nft_trans_elem_alloc(ctx, NFT_MSG_NEWSETELEM, set); if (trans == NULL) { err = -ENOMEM; - goto err_elem_expr; + goto err_elem_free; } ext->genmask = nft_genmask_cur(ctx->net) | NFT_SET_ELEM_BUSY_MASK; @@ -6126,10 +6178,10 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set, nft_setelem_remove(ctx->net, set, &elem); err_element_clash: kfree(trans); -err_elem_expr: +err_elem_free: if (obj) obj->use--; - +err_elem_userdata: nf_tables_set_elem_destroy(ctx, set, elem.priv); err_parse_data: if (nla[NFTA_SET_ELEM_DATA] != NULL) @@ -6311,8 +6363,10 @@ static int nft_del_setelem(struct nft_ctx *ctx, struct nft_set *set, elem.priv = nft_set_elem_init(set, &tmpl, elem.key.val.data, elem.key_end.val.data, NULL, 0, 0, GFP_KERNEL_ACCOUNT); - if (elem.priv == NULL) + if (IS_ERR(elem.priv)) { + err = PTR_ERR(elem.priv); goto fail_elem_key_end; + } ext = nft_set_elem_ext(set, elem.priv); if (flags) diff --git a/net/netfilter/nft_dynset.c b/net/netfilter/nft_dynset.c index 22f70b543fa2..6983e6ddeef9 100644 --- a/net/netfilter/nft_dynset.c +++ b/net/netfilter/nft_dynset.c @@ -60,7 +60,7 @@ static void *nft_dynset_new(struct nft_set *set, const struct nft_expr *expr, ®s->data[priv->sreg_key], NULL, ®s->data[priv->sreg_data], timeout, 0, GFP_ATOMIC); - if (elem == NULL) + if (IS_ERR(elem)) goto err1; ext = nft_set_elem_ext(set, elem); From 470ee20e069a6d05ae549f7d0ef2bdbcee6a81b2 Mon Sep 17 00:00:00 2001 From: Thadeu Lima de Souza Cascardo Date: Tue, 9 Aug 2022 14:01:46 -0300 Subject: [PATCH 2/8] netfilter: nf_tables: do not allow SET_ID to refer to another table When doing lookups for sets on the same batch by using its ID, a set from a different table can be used. Then, when the table is removed, a reference to the set may be kept after the set is freed, leading to a potential use-after-free. When looking for sets by ID, use the table that was used for the lookup by name, and only return sets belonging to that same table. This fixes CVE-2022-2586, also reported as ZDI-CAN-17470. Reported-by: Team Orca of Sea Security (@seasecresponse) Fixes: 958bee14d071 ("netfilter: nf_tables: use new transaction infrastructure to handle sets") Signed-off-by: Thadeu Lima de Souza Cascardo Cc: Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_tables_api.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 3b09e13b9b5c..41c529b0001c 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -3842,6 +3842,7 @@ static struct nft_set *nft_set_lookup_byhandle(const struct nft_table *table, } static struct nft_set *nft_set_lookup_byid(const struct net *net, + const struct nft_table *table, const struct nlattr *nla, u8 genmask) { struct nftables_pernet *nft_net = nft_pernet(net); @@ -3853,6 +3854,7 @@ static struct nft_set *nft_set_lookup_byid(const struct net *net, struct nft_set *set = nft_trans_set(trans); if (id == nft_trans_set_id(trans) && + set->table == table && nft_active_genmask(set, genmask)) return set; } @@ -3873,7 +3875,7 @@ struct nft_set *nft_set_lookup_global(const struct net *net, if (!nla_set_id) return set; - set = nft_set_lookup_byid(net, nla_set_id, genmask); + set = nft_set_lookup_byid(net, table, nla_set_id, genmask); } return set; } From 95f466d22364a33d183509629d0879885b4f547e Mon Sep 17 00:00:00 2001 From: Thadeu Lima de Souza Cascardo Date: Tue, 9 Aug 2022 14:01:47 -0300 Subject: [PATCH 3/8] netfilter: nf_tables: do not allow CHAIN_ID to refer to another table When doing lookups for chains on the same batch by using its ID, a chain from a different table can be used. If a rule is added to a table but refers to a chain in a different table, it will be linked to the chain in table2, but would have expressions referring to objects in table1. Then, when table1 is removed, the rule will not be removed as its linked to a chain in table2. When expressions in the rule are processed or removed, that will lead to a use-after-free. When looking for chains by ID, use the table that was used for the lookup by name, and only return chains belonging to that same table. Fixes: 837830a4b439 ("netfilter: nf_tables: add NFTA_RULE_CHAIN_ID attribute") Signed-off-by: Thadeu Lima de Souza Cascardo Cc: Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_tables_api.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 41c529b0001c..041accbaca32 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -2472,6 +2472,7 @@ static int nf_tables_updchain(struct nft_ctx *ctx, u8 genmask, u8 policy, } static struct nft_chain *nft_chain_lookup_byid(const struct net *net, + const struct nft_table *table, const struct nlattr *nla) { struct nftables_pernet *nft_net = nft_pernet(net); @@ -2482,6 +2483,7 @@ static struct nft_chain *nft_chain_lookup_byid(const struct net *net, struct nft_chain *chain = trans->ctx.chain; if (trans->msg_type == NFT_MSG_NEWCHAIN && + chain->table == table && id == nft_trans_chain_id(trans)) return chain; } @@ -3417,7 +3419,7 @@ static int nf_tables_newrule(struct sk_buff *skb, const struct nfnl_info *info, return -EOPNOTSUPP; } else if (nla[NFTA_RULE_CHAIN_ID]) { - chain = nft_chain_lookup_byid(net, nla[NFTA_RULE_CHAIN_ID]); + chain = nft_chain_lookup_byid(net, table, nla[NFTA_RULE_CHAIN_ID]); if (IS_ERR(chain)) { NL_SET_BAD_ATTR(extack, nla[NFTA_RULE_CHAIN_ID]); return PTR_ERR(chain); @@ -9661,7 +9663,7 @@ static int nft_verdict_init(const struct nft_ctx *ctx, struct nft_data *data, tb[NFTA_VERDICT_CHAIN], genmask); } else if (tb[NFTA_VERDICT_CHAIN_ID]) { - chain = nft_chain_lookup_byid(ctx->net, + chain = nft_chain_lookup_byid(ctx->net, ctx->table, tb[NFTA_VERDICT_CHAIN_ID]); if (IS_ERR(chain)) return PTR_ERR(chain); From 36d5b2913219ac853908b0f1c664345e04313856 Mon Sep 17 00:00:00 2001 From: Thadeu Lima de Souza Cascardo Date: Tue, 9 Aug 2022 14:01:48 -0300 Subject: [PATCH 4/8] netfilter: nf_tables: do not allow RULE_ID to refer to another chain When doing lookups for rules on the same batch by using its ID, a rule from a different chain can be used. If a rule is added to a chain but tries to be positioned next to a rule from a different chain, it will be linked to chain2, but the use counter on chain1 would be the one to be incremented. When looking for rules by ID, use the chain that was used for the lookup by name. The chain used in the context copied to the transaction needs to match that same chain. That way, struct nft_rule does not need to get enlarged with another member. Fixes: 1a94e38d254b ("netfilter: nf_tables: add NFTA_RULE_ID attribute") Fixes: 75dd48e2e420 ("netfilter: nf_tables: Support RULE_ID reference in new rule") Signed-off-by: Thadeu Lima de Souza Cascardo Cc: Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_tables_api.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 041accbaca32..0c3c0523e5f2 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -3373,6 +3373,7 @@ static int nft_table_validate(struct net *net, const struct nft_table *table) } static struct nft_rule *nft_rule_lookup_byid(const struct net *net, + const struct nft_chain *chain, const struct nlattr *nla); #define NFT_RULE_MAXEXPRS 128 @@ -3461,7 +3462,7 @@ static int nf_tables_newrule(struct sk_buff *skb, const struct nfnl_info *info, return PTR_ERR(old_rule); } } else if (nla[NFTA_RULE_POSITION_ID]) { - old_rule = nft_rule_lookup_byid(net, nla[NFTA_RULE_POSITION_ID]); + old_rule = nft_rule_lookup_byid(net, chain, nla[NFTA_RULE_POSITION_ID]); if (IS_ERR(old_rule)) { NL_SET_BAD_ATTR(extack, nla[NFTA_RULE_POSITION_ID]); return PTR_ERR(old_rule); @@ -3606,6 +3607,7 @@ static int nf_tables_newrule(struct sk_buff *skb, const struct nfnl_info *info, } static struct nft_rule *nft_rule_lookup_byid(const struct net *net, + const struct nft_chain *chain, const struct nlattr *nla) { struct nftables_pernet *nft_net = nft_pernet(net); @@ -3616,6 +3618,7 @@ static struct nft_rule *nft_rule_lookup_byid(const struct net *net, struct nft_rule *rule = nft_trans_rule(trans); if (trans->msg_type == NFT_MSG_NEWRULE && + trans->ctx.chain == chain && id == nft_trans_rule_id(trans)) return rule; } @@ -3665,7 +3668,7 @@ static int nf_tables_delrule(struct sk_buff *skb, const struct nfnl_info *info, err = nft_delrule(&ctx, rule); } else if (nla[NFTA_RULE_ID]) { - rule = nft_rule_lookup_byid(net, nla[NFTA_RULE_ID]); + rule = nft_rule_lookup_byid(net, chain, nla[NFTA_RULE_ID]); if (IS_ERR(rule)) { NL_SET_BAD_ATTR(extack, nla[NFTA_RULE_ID]); return PTR_ERR(rule); From 134941683b89d05b5e5c28c817c95049ba409d01 Mon Sep 17 00:00:00 2001 From: Christophe JAILLET Date: Sat, 6 Aug 2022 17:39:20 +0200 Subject: [PATCH 5/8] netfilter: ip6t_LOG: Fix a typo in a comment s/_IPT_LOG_H/_IP6T_LOG_H/ While at it add some surrounding space to ease reading. Signed-off-by: Christophe JAILLET Signed-off-by: Pablo Neira Ayuso --- include/uapi/linux/netfilter_ipv6/ip6t_LOG.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/uapi/linux/netfilter_ipv6/ip6t_LOG.h b/include/uapi/linux/netfilter_ipv6/ip6t_LOG.h index 23e91a9c2583..0b7b16dbdec2 100644 --- a/include/uapi/linux/netfilter_ipv6/ip6t_LOG.h +++ b/include/uapi/linux/netfilter_ipv6/ip6t_LOG.h @@ -17,4 +17,4 @@ struct ip6t_log_info { char prefix[30]; }; -#endif /*_IPT_LOG_H*/ +#endif /* _IP6T_LOG_H */ From 341b6941608762d8235f3fd1e45e4d7114ed8c2c Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Mon, 8 Aug 2022 19:30:06 +0200 Subject: [PATCH 6/8] netfilter: nf_tables: upfront validation of data via nft_data_init() Instead of parsing the data and then validate that type and length are correct, pass a description of the expected data so it can be validated upfront before parsing it to bail out earlier. This patch adds a new .size field to specify the maximum size of the data area. The .len field is optional and it is used as an input/output field, it provides the specific length of the expected data in the input path. If then .len field is not specified, then obtained length from the netlink attribute is stored. This is required by cmp, bitwise, range and immediate, which provide no netlink attribute that describes the data length. The immediate expression uses the destination register type to infer the expected data type. Relying on opencoded validation of the expected data might lead to subtle bugs as described in 7e6bc1f6cabc ("netfilter: nf_tables: stricter validation of element data"). Signed-off-by: Pablo Neira Ayuso --- include/net/netfilter/nf_tables.h | 4 +- net/netfilter/nf_tables_api.c | 78 ++++++++++++++++--------------- net/netfilter/nft_bitwise.c | 66 +++++++++++++------------- net/netfilter/nft_cmp.c | 44 ++++++++--------- net/netfilter/nft_immediate.c | 22 +++++++-- net/netfilter/nft_range.c | 27 +++++------ 6 files changed, 126 insertions(+), 115 deletions(-) diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h index 7ece4fd0cf66..1554f1e7215b 100644 --- a/include/net/netfilter/nf_tables.h +++ b/include/net/netfilter/nf_tables.h @@ -223,11 +223,11 @@ struct nft_ctx { struct nft_data_desc { enum nft_data_types type; + unsigned int size; unsigned int len; }; -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); diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 0c3c0523e5f2..05896765c68f 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -5202,19 +5202,13 @@ static int nft_setelem_parse_flags(const struct nft_set *set, static int nft_setelem_parse_key(struct nft_ctx *ctx, struct nft_set *set, struct nft_data *key, struct nlattr *attr) { - struct nft_data_desc desc; - int err; + struct nft_data_desc desc = { + .type = NFT_DATA_VALUE, + .size = NFT_DATA_VALUE_MAXLEN, + .len = set->klen, + }; - err = nft_data_init(ctx, key, NFT_DATA_VALUE_MAXLEN, &desc, attr); - if (err < 0) - return err; - - if (desc.type != NFT_DATA_VALUE || desc.len != set->klen) { - nft_data_release(key, desc.type); - return -EINVAL; - } - - return 0; + return nft_data_init(ctx, key, &desc, attr); } static int nft_setelem_parse_data(struct nft_ctx *ctx, struct nft_set *set, @@ -5223,24 +5217,17 @@ static int nft_setelem_parse_data(struct nft_ctx *ctx, struct nft_set *set, struct nlattr *attr) { u32 dtype; - int err; - - err = nft_data_init(ctx, data, NFT_DATA_VALUE_MAXLEN, desc, attr); - if (err < 0) - return err; if (set->dtype == NFT_DATA_VERDICT) dtype = NFT_DATA_VERDICT; else dtype = NFT_DATA_VALUE; - if (dtype != desc->type || - set->dlen != desc->len) { - nft_data_release(data, desc->type); - return -EINVAL; - } + desc->type = dtype; + desc->size = NFT_DATA_VALUE_MAXLEN; + desc->len = set->dlen; - return 0; + return nft_data_init(ctx, data, desc, attr); } static void *nft_setelem_catchall_get(const struct net *net, @@ -9685,7 +9672,7 @@ static int nft_verdict_init(const struct nft_ctx *ctx, struct nft_data *data, } desc->len = sizeof(data->verdict); - desc->type = NFT_DATA_VERDICT; + return 0; } @@ -9738,20 +9725,25 @@ int nft_verdict_dump(struct sk_buff *skb, int type, const struct nft_verdict *v) } static int nft_value_init(const struct nft_ctx *ctx, - struct nft_data *data, unsigned int size, - struct nft_data_desc *desc, const struct nlattr *nla) + struct nft_data *data, struct nft_data_desc *desc, + const struct nlattr *nla) { unsigned int len; len = nla_len(nla); if (len == 0) return -EINVAL; - if (len > size) + if (len > desc->size) return -EOVERFLOW; + if (desc->len) { + if (len != desc->len) + return -EINVAL; + } else { + desc->len = len; + } nla_memcpy(data->data, nla, len); - desc->type = NFT_DATA_VALUE; - desc->len = len; + return 0; } @@ -9771,7 +9763,6 @@ static const struct nla_policy nft_data_policy[NFTA_DATA_MAX + 1] = { * * @ctx: context of the expression using the data * @data: destination struct nft_data - * @size: maximum data length * @desc: data description * @nla: netlink attribute containing data * @@ -9781,24 +9772,35 @@ static const struct nla_policy nft_data_policy[NFTA_DATA_MAX + 1] = { * The caller can indicate that it only wants to accept data of type * NFT_DATA_VALUE by passing NULL for the ctx argument. */ -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) { struct nlattr *tb[NFTA_DATA_MAX + 1]; int err; + if (WARN_ON_ONCE(!desc->size)) + return -EINVAL; + err = nla_parse_nested_deprecated(tb, NFTA_DATA_MAX, nla, nft_data_policy, NULL); if (err < 0) return err; - if (tb[NFTA_DATA_VALUE]) - return nft_value_init(ctx, data, size, desc, - tb[NFTA_DATA_VALUE]); - if (tb[NFTA_DATA_VERDICT] && ctx != NULL) - return nft_verdict_init(ctx, data, desc, tb[NFTA_DATA_VERDICT]); - return -EINVAL; + if (tb[NFTA_DATA_VALUE]) { + if (desc->type != NFT_DATA_VALUE) + return -EINVAL; + + err = nft_value_init(ctx, data, desc, tb[NFTA_DATA_VALUE]); + } else if (tb[NFTA_DATA_VERDICT] && ctx != NULL) { + if (desc->type != NFT_DATA_VERDICT) + return -EINVAL; + + err = nft_verdict_init(ctx, data, desc, tb[NFTA_DATA_VERDICT]); + } else { + err = -EINVAL; + } + + return err; } EXPORT_SYMBOL_GPL(nft_data_init); diff --git a/net/netfilter/nft_bitwise.c b/net/netfilter/nft_bitwise.c index 83590afe3768..e6e402b247d0 100644 --- a/net/netfilter/nft_bitwise.c +++ b/net/netfilter/nft_bitwise.c @@ -93,7 +93,16 @@ static const struct nla_policy nft_bitwise_policy[NFTA_BITWISE_MAX + 1] = { static int nft_bitwise_init_bool(struct nft_bitwise *priv, const struct nlattr *const tb[]) { - struct nft_data_desc mask, xor; + struct nft_data_desc mask = { + .type = NFT_DATA_VALUE, + .size = sizeof(priv->mask), + .len = priv->len, + }; + struct nft_data_desc xor = { + .type = NFT_DATA_VALUE, + .size = sizeof(priv->xor), + .len = priv->len, + }; int err; if (tb[NFTA_BITWISE_DATA]) @@ -103,37 +112,30 @@ static int nft_bitwise_init_bool(struct nft_bitwise *priv, !tb[NFTA_BITWISE_XOR]) return -EINVAL; - err = nft_data_init(NULL, &priv->mask, sizeof(priv->mask), &mask, - tb[NFTA_BITWISE_MASK]); + err = nft_data_init(NULL, &priv->mask, &mask, tb[NFTA_BITWISE_MASK]); if (err < 0) return err; - if (mask.type != NFT_DATA_VALUE || mask.len != priv->len) { - err = -EINVAL; - goto err_mask_release; - } - err = nft_data_init(NULL, &priv->xor, sizeof(priv->xor), &xor, - tb[NFTA_BITWISE_XOR]); + err = nft_data_init(NULL, &priv->xor, &xor, tb[NFTA_BITWISE_XOR]); if (err < 0) - goto err_mask_release; - if (xor.type != NFT_DATA_VALUE || xor.len != priv->len) { - err = -EINVAL; - goto err_xor_release; - } + goto err_xor_err; return 0; -err_xor_release: - nft_data_release(&priv->xor, xor.type); -err_mask_release: +err_xor_err: nft_data_release(&priv->mask, mask.type); + return err; } static int nft_bitwise_init_shift(struct nft_bitwise *priv, const struct nlattr *const tb[]) { - struct nft_data_desc d; + struct nft_data_desc desc = { + .type = NFT_DATA_VALUE, + .size = sizeof(priv->data), + .len = sizeof(u32), + }; int err; if (tb[NFTA_BITWISE_MASK] || @@ -143,13 +145,12 @@ static int nft_bitwise_init_shift(struct nft_bitwise *priv, if (!tb[NFTA_BITWISE_DATA]) return -EINVAL; - err = nft_data_init(NULL, &priv->data, sizeof(priv->data), &d, - tb[NFTA_BITWISE_DATA]); + err = nft_data_init(NULL, &priv->data, &desc, tb[NFTA_BITWISE_DATA]); if (err < 0) return err; - if (d.type != NFT_DATA_VALUE || d.len != sizeof(u32) || - priv->data.data[0] >= BITS_PER_TYPE(u32)) { - nft_data_release(&priv->data, d.type); + + if (priv->data.data[0] >= BITS_PER_TYPE(u32)) { + nft_data_release(&priv->data, desc.type); return -EINVAL; } @@ -339,22 +340,21 @@ static const struct nft_expr_ops nft_bitwise_ops = { static int nft_bitwise_extract_u32_data(const struct nlattr * const tb, u32 *out) { - struct nft_data_desc desc; struct nft_data data; - int err = 0; + struct nft_data_desc desc = { + .type = NFT_DATA_VALUE, + .size = sizeof(data), + .len = sizeof(u32), + }; + int err; - err = nft_data_init(NULL, &data, sizeof(data), &desc, tb); + err = nft_data_init(NULL, &data, &desc, tb); if (err < 0) return err; - if (desc.type != NFT_DATA_VALUE || desc.len != sizeof(u32)) { - err = -EINVAL; - goto err; - } *out = data.data[0]; -err: - nft_data_release(&data, desc.type); - return err; + + return 0; } static int nft_bitwise_fast_init(const struct nft_ctx *ctx, diff --git a/net/netfilter/nft_cmp.c b/net/netfilter/nft_cmp.c index 777f09e4dc60..963cf831799c 100644 --- a/net/netfilter/nft_cmp.c +++ b/net/netfilter/nft_cmp.c @@ -73,20 +73,16 @@ static int nft_cmp_init(const struct nft_ctx *ctx, const struct nft_expr *expr, const struct nlattr * const tb[]) { struct nft_cmp_expr *priv = nft_expr_priv(expr); - struct nft_data_desc desc; + struct nft_data_desc desc = { + .type = NFT_DATA_VALUE, + .size = sizeof(priv->data), + }; int err; - err = nft_data_init(NULL, &priv->data, sizeof(priv->data), &desc, - tb[NFTA_CMP_DATA]); + err = nft_data_init(NULL, &priv->data, &desc, tb[NFTA_CMP_DATA]); if (err < 0) return err; - if (desc.type != NFT_DATA_VALUE) { - err = -EINVAL; - nft_data_release(&priv->data, desc.type); - return err; - } - err = nft_parse_register_load(tb[NFTA_CMP_SREG], &priv->sreg, desc.len); if (err < 0) return err; @@ -214,12 +210,14 @@ static int nft_cmp_fast_init(const struct nft_ctx *ctx, const struct nlattr * const tb[]) { struct nft_cmp_fast_expr *priv = nft_expr_priv(expr); - struct nft_data_desc desc; struct nft_data data; + struct nft_data_desc desc = { + .type = NFT_DATA_VALUE, + .size = sizeof(data), + }; int err; - err = nft_data_init(NULL, &data, sizeof(data), &desc, - tb[NFTA_CMP_DATA]); + err = nft_data_init(NULL, &data, &desc, tb[NFTA_CMP_DATA]); if (err < 0) return err; @@ -313,11 +311,13 @@ static int nft_cmp16_fast_init(const struct nft_ctx *ctx, const struct nlattr * const tb[]) { struct nft_cmp16_fast_expr *priv = nft_expr_priv(expr); - struct nft_data_desc desc; + struct nft_data_desc desc = { + .type = NFT_DATA_VALUE, + .size = sizeof(priv->data), + }; int err; - err = nft_data_init(NULL, &priv->data, sizeof(priv->data), &desc, - tb[NFTA_CMP_DATA]); + err = nft_data_init(NULL, &priv->data, &desc, tb[NFTA_CMP_DATA]); if (err < 0) return err; @@ -380,8 +380,11 @@ const struct nft_expr_ops nft_cmp16_fast_ops = { static const struct nft_expr_ops * nft_cmp_select_ops(const struct nft_ctx *ctx, const struct nlattr * const tb[]) { - struct nft_data_desc desc; struct nft_data data; + struct nft_data_desc desc = { + .type = NFT_DATA_VALUE, + .size = sizeof(data), + }; enum nft_cmp_ops op; u8 sreg; int err; @@ -404,14 +407,10 @@ nft_cmp_select_ops(const struct nft_ctx *ctx, const struct nlattr * const tb[]) return ERR_PTR(-EINVAL); } - err = nft_data_init(NULL, &data, sizeof(data), &desc, - tb[NFTA_CMP_DATA]); + err = nft_data_init(NULL, &data, &desc, tb[NFTA_CMP_DATA]); if (err < 0) return ERR_PTR(err); - if (desc.type != NFT_DATA_VALUE) - goto err1; - sreg = ntohl(nla_get_be32(tb[NFTA_CMP_SREG])); if (op == NFT_CMP_EQ || op == NFT_CMP_NEQ) { @@ -423,9 +422,6 @@ nft_cmp_select_ops(const struct nft_ctx *ctx, const struct nlattr * const tb[]) return &nft_cmp16_fast_ops; } return &nft_cmp_ops; -err1: - nft_data_release(&data, desc.type); - return ERR_PTR(-EINVAL); } struct nft_expr_type nft_cmp_type __read_mostly = { diff --git a/net/netfilter/nft_immediate.c b/net/netfilter/nft_immediate.c index b80f7b507349..5f28b21abc7d 100644 --- a/net/netfilter/nft_immediate.c +++ b/net/netfilter/nft_immediate.c @@ -29,20 +29,36 @@ static const struct nla_policy nft_immediate_policy[NFTA_IMMEDIATE_MAX + 1] = { [NFTA_IMMEDIATE_DATA] = { .type = NLA_NESTED }, }; +static enum nft_data_types nft_reg_to_type(const struct nlattr *nla) +{ + enum nft_data_types type; + u8 reg; + + reg = ntohl(nla_get_be32(nla)); + if (reg == NFT_REG_VERDICT) + type = NFT_DATA_VERDICT; + else + type = NFT_DATA_VALUE; + + return type; +} + static int nft_immediate_init(const struct nft_ctx *ctx, const struct nft_expr *expr, const struct nlattr * const tb[]) { struct nft_immediate_expr *priv = nft_expr_priv(expr); - struct nft_data_desc desc; + struct nft_data_desc desc = { + .size = sizeof(priv->data), + }; int err; if (tb[NFTA_IMMEDIATE_DREG] == NULL || tb[NFTA_IMMEDIATE_DATA] == NULL) return -EINVAL; - err = nft_data_init(ctx, &priv->data, sizeof(priv->data), &desc, - tb[NFTA_IMMEDIATE_DATA]); + desc.type = nft_reg_to_type(tb[NFTA_IMMEDIATE_DREG]); + err = nft_data_init(ctx, &priv->data, &desc, tb[NFTA_IMMEDIATE_DATA]); if (err < 0) return err; diff --git a/net/netfilter/nft_range.c b/net/netfilter/nft_range.c index 66f77484c227..832f0d725a9e 100644 --- a/net/netfilter/nft_range.c +++ b/net/netfilter/nft_range.c @@ -51,7 +51,14 @@ static int nft_range_init(const struct nft_ctx *ctx, const struct nft_expr *expr const struct nlattr * const tb[]) { struct nft_range_expr *priv = nft_expr_priv(expr); - struct nft_data_desc desc_from, desc_to; + struct nft_data_desc desc_from = { + .type = NFT_DATA_VALUE, + .size = sizeof(priv->data_from), + }; + struct nft_data_desc desc_to = { + .type = NFT_DATA_VALUE, + .size = sizeof(priv->data_to), + }; int err; u32 op; @@ -61,26 +68,16 @@ static int nft_range_init(const struct nft_ctx *ctx, const struct nft_expr *expr !tb[NFTA_RANGE_TO_DATA]) return -EINVAL; - err = nft_data_init(NULL, &priv->data_from, sizeof(priv->data_from), - &desc_from, tb[NFTA_RANGE_FROM_DATA]); + err = nft_data_init(NULL, &priv->data_from, &desc_from, + tb[NFTA_RANGE_FROM_DATA]); if (err < 0) return err; - if (desc_from.type != NFT_DATA_VALUE) { - err = -EINVAL; - goto err1; - } - - err = nft_data_init(NULL, &priv->data_to, sizeof(priv->data_to), - &desc_to, tb[NFTA_RANGE_TO_DATA]); + err = nft_data_init(NULL, &priv->data_to, &desc_to, + tb[NFTA_RANGE_TO_DATA]); if (err < 0) goto err1; - if (desc_to.type != NFT_DATA_VALUE) { - err = -EINVAL; - goto err2; - } - if (desc_from.len != desc_to.len) { err = -EINVAL; goto err2; From f323ef3a0d49e147365284bc1f02212e617b7f09 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Mon, 8 Aug 2022 19:30:07 +0200 Subject: [PATCH 7/8] netfilter: nf_tables: disallow jump to implicit chain from set element Extend struct nft_data_desc to add a flag field that specifies nft_data_init() is being called for set element data. Use it to disallow jump to implicit chain from set element, only jump to chain via immediate expression is allowed. Fixes: d0e2c7de92c7 ("netfilter: nf_tables: add NFT_CHAIN_BINDING") Signed-off-by: Pablo Neira Ayuso --- include/net/netfilter/nf_tables.h | 5 +++++ net/netfilter/nf_tables_api.c | 4 ++++ 2 files changed, 9 insertions(+) diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h index 1554f1e7215b..99aae36c04b9 100644 --- a/include/net/netfilter/nf_tables.h +++ b/include/net/netfilter/nf_tables.h @@ -221,10 +221,15 @@ 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, diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 05896765c68f..460b0925ea60 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -5226,6 +5226,7 @@ static int nft_setelem_parse_data(struct nft_ctx *ctx, struct nft_set *set, desc->type = dtype; desc->size = NFT_DATA_VALUE_MAXLEN; desc->len = set->dlen; + desc->flags = NFT_DATA_DESC_SETELEM; return nft_data_init(ctx, data, desc, attr); } @@ -9665,6 +9666,9 @@ static int nft_verdict_init(const struct nft_ctx *ctx, struct nft_data *data, return PTR_ERR(chain); if (nft_is_base_chain(chain)) return -EOPNOTSUPP; + if (desc->flags & NFT_DATA_DESC_SETELEM && + chain->flags & NFT_CHAIN_BINDING) + return -EINVAL; chain->use++; data->verdict.chain = chain; From 580077855a40741cf511766129702d97ff02f4d9 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Tue, 9 Aug 2022 18:34:02 +0200 Subject: [PATCH 8/8] netfilter: nf_tables: fix null deref due to zeroed list head In nf_tables_updtable, if nf_tables_table_enable returns an error, nft_trans_destroy is called to free the transaction object. nft_trans_destroy() calls list_del(), but the transaction was never placed on a list -- the list head is all zeroes, this results in a null dereference: BUG: KASAN: null-ptr-deref in nft_trans_destroy+0x26/0x59 Call Trace: nft_trans_destroy+0x26/0x59 nf_tables_newtable+0x4bc/0x9bc [..] Its sane to assume that nft_trans_destroy() can be called on the transaction object returned by nft_trans_alloc(), so make sure the list head is initialised. Fixes: 55dd6f93076b ("netfilter: nf_tables: use new transaction infrastructure to handle table") Reported-by: mingi cho Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_tables_api.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 460b0925ea60..3cc88998b879 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -153,6 +153,7 @@ static struct nft_trans *nft_trans_alloc_gfp(const struct nft_ctx *ctx, if (trans == NULL) return NULL; + INIT_LIST_HEAD(&trans->list); trans->msg_type = msg_type; trans->ctx = *ctx;