netfilter: nf_tables: disallow element updates of bound anonymous sets

[ Upstream commit c88c535b592d3baeee74009f3eceeeaf0fdd5e1b ]

Anonymous sets come with NFT_SET_CONSTANT from userspace. Although API
allows to create anonymous sets without NFT_SET_CONSTANT, it makes no
sense to allow to add and to delete elements for bound anonymous sets.

Fixes: 96518518cc41 ("netfilter: add nftables")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 337bab6..2cd83d0 100644 (file)
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -6590,7 +6590,8 @@ static int nf_tables_newsetelem(struct sk_buff *skb,
        if (IS_ERR(set))
                return PTR_ERR(set);
 
-       if (!list_empty(&set->bindings) && set->flags & NFT_SET_CONSTANT)
+       if (!list_empty(&set->bindings) &&
+           (set->flags & (NFT_SET_CONSTANT | NFT_SET_ANONYMOUS)))
                return -EBUSY;
 
        nft_ctx_init(&ctx, net, skb, info->nlh, family, table, NULL, nla);
@@ -6864,7 +6865,9 @@ static int nf_tables_delsetelem(struct sk_buff *skb,
        set = nft_set_lookup(table, nla[NFTA_SET_ELEM_LIST_SET], genmask);
        if (IS_ERR(set))
                return PTR_ERR(set);
-       if (!list_empty(&set->bindings) && set->flags & NFT_SET_CONSTANT)
+
+       if (!list_empty(&set->bindings) &&
+           (set->flags & (NFT_SET_CONSTANT | NFT_SET_ANONYMOUS)))
                return -EBUSY;
 
        nft_ctx_init(&ctx, net, skb, info->nlh, family, table, NULL, nla);