From e31f072ffab0397a328b31a9589dcf9733dc9c72 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Tue, 22 Jun 2021 12:10:49 +0200 Subject: [PATCH] netfilter: nf_tables: do not allow to delete table with owner by handle nft_table_lookup_byhandle() also needs to validate the netlink PortID owner when deleting a table by handle. Fixes: 6001a930ce03 ("netfilter: nftables: introduce table ownership") Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_tables_api.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 1d62b1a..fcb15b89 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -583,7 +583,7 @@ static struct nft_table *nft_table_lookup(const struct net *net, static struct nft_table *nft_table_lookup_byhandle(const struct net *net, const struct nlattr *nla, - u8 genmask) + u8 genmask, u32 nlpid) { struct nftables_pernet *nft_net; struct nft_table *table; @@ -591,8 +591,13 @@ static struct nft_table *nft_table_lookup_byhandle(const struct net *net, nft_net = nft_pernet(net); list_for_each_entry(table, &nft_net->tables, list) { if (be64_to_cpu(nla_get_be64(nla)) == table->handle && - nft_active_genmask(table, genmask)) + nft_active_genmask(table, genmask)) { + if (nft_table_has_owner(table) && + nlpid && table->nlpid != nlpid) + return ERR_PTR(-EPERM); + return table; + } } return ERR_PTR(-ENOENT); @@ -1279,7 +1284,8 @@ static int nf_tables_deltable(struct sk_buff *skb, const struct nfnl_info *info, if (nla[NFTA_TABLE_HANDLE]) { attr = nla[NFTA_TABLE_HANDLE]; - table = nft_table_lookup_byhandle(net, attr, genmask); + table = nft_table_lookup_byhandle(net, attr, genmask, + NETLINK_CB(skb).portid); } else { attr = nla[NFTA_TABLE_NAME]; table = nft_table_lookup(net, attr, family, genmask, -- 2.7.4