summaryrefslogtreecommitdiff
path: root/net
diff options
context:
space:
mode:
authorThadeu Lima de Souza Cascardo <cascardo@canonical.com>2022-08-09 14:01:47 -0300
committerPablo Neira Ayuso <pablo@netfilter.org>2022-08-09 19:38:17 +0200
commit95f466d22364a33d183509629d0879885b4f547e (patch)
treedb39d7ee842fc6f8ac40f5fce726a097da329860 /net
parent470ee20e069a6d05ae549f7d0ef2bdbcee6a81b2 (diff)
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 <cascardo@canonical.com> Cc: <stable@vger.kernel.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net')
-rw-r--r--net/netfilter/nf_tables_api.c6
1 files 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 @@ err:
}
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);