This is a note to let you know that I've just added the patch titled netfilter: nf_tables: disallow element removal on anonymous sets to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: netfilter-nf_tables-disallow-element-removal-on-anon.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit be4df9f2962c981c10b96018d06d0ac6c32b5da6 Author: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx> Date: Sun Sep 10 19:04:45 2023 +0200 netfilter: nf_tables: disallow element removal on anonymous sets [ Upstream commit 23a3bfd4ba7acd36abf52b78605f61b21bdac216 ] Anonymous sets need to be populated once at creation and then they are bound to rule since 938154b93be8 ("netfilter: nf_tables: reject unbound anonymous set before commit phase"), otherwise transaction reports EINVAL. Userspace does not need to delete elements of anonymous sets that are not yet bound, reject this with EOPNOTSUPP. From flush command path, skip anonymous sets, they are expected to be bound already. Otherwise, EINVAL is hit at the end of this transaction for unbound sets. Fixes: 96518518cc41 ("netfilter: add nftables") Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index a1a1f715fb624..9fc4431242e2a 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -1047,8 +1047,7 @@ static int nft_flush_table(struct nft_ctx *ctx) if (!nft_is_active_next(ctx->net, set)) continue; - if (nft_set_is_anonymous(set) && - !list_empty(&set->bindings)) + if (nft_set_is_anonymous(set)) continue; err = nft_delset(ctx, set); @@ -5066,8 +5065,10 @@ static int nf_tables_delsetelem(struct net *net, struct sock *nlsk, if (IS_ERR(set)) return PTR_ERR(set); - if (!list_empty(&set->bindings) && - (set->flags & (NFT_SET_CONSTANT | NFT_SET_ANONYMOUS))) + if (nft_set_is_anonymous(set)) + return -EOPNOTSUPP; + + if (!list_empty(&set->bindings) && (set->flags & NFT_SET_CONSTANT)) return -EBUSY; if (nla[NFTA_SET_ELEM_LIST_ELEMENTS] == NULL) {