Commit b389139f authored Jun 26, 2023 by Pablo Neira Ayuso

netfilter: nf_tables: fix underflow in chain reference counter



Set element addition error path decrements reference counter on chains
twice: once on element release and again via nft_data_release().

Then, d6b47866 ("netfilter: nf_tables: fix underflow in object
reference counter") incorrectly fixed this by removing the stateful
object reference count decrement.

Restore the stateful object decrement as in b91d9036 ("netfilter:
nf_tables: fix leaking object reference count") and let
nft_data_release() decrement the chain reference counter, so this is
done only once.

Fixes: d6b47866 ("netfilter: nf_tables: fix underflow in object reference counter")
Fixes: 628bd3e4 ("netfilter: nf_tables: drop map element references from preparation phase")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

parent 3e704897

net/netfilter/nf_tables_api.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -6771,7 +6771,9 @@ static int nft_add_set_elem(struct nft_ctx ctx, struct nft_set set,
		err_element_clash:
		kfree(trans);
		err_elem_free:
		nft_set_elem_destroy(set, elem.priv, true);
		nf_tables_set_elem_destroy(ctx, set, elem.priv);
		if (obj)
		obj->use--;
		err_parse_data:
		if (nla[NFTA_SET_ELEM_DATA] != NULL)
		nft_data_release(&elem.data.val, desc.type);