[PATCH nf-next] netfilter: nf_tables: fix wrong transaction ordering in set elements

[PATCH nf-next] netfilter: nf_tables: fix wrong transaction ordering in set elements

[Pablo Neira Ayuso]

The transaction needs to be placed at the end of the commit list,
otherwise event notifications are reordered and we may crash when
releasing object via call_rcu.

This problem was introduced in 60319eb ("netfilter: nf_tables: use new
transaction infrastructure to handle elements").

Reported-by: Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nf_tables_api.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index e171c63..ca38725 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -3076,7 +3076,7 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
 		goto err4;
 
 	nft_trans_elem(trans) = elem;
-	list_add(&trans->list, &ctx->net->nft.commit_list);
+	list_add_tail(&trans->list, &ctx->net->nft.commit_list);
 	return 0;
 
 err4:
@@ -3160,7 +3160,7 @@ static int nft_del_setelem(struct nft_ctx *ctx, struct nft_set *set,
 		goto err2;
 
 	nft_trans_elem(trans) = elem;
-	list_add(&trans->list, &ctx->net->nft.commit_list);
+	list_add_tail(&trans->list, &ctx->net->nft.commit_list);
 
 	nft_data_uninit(&elem.key, NFT_DATA_VALUE);
 	if (set->flags & NFT_SET_MAP)
-- 
1.7.10.4