If no NLM_F_EXCL is specified and the element already exists, no error is reported to userspace. However, no new element is added so decrement set->nelem to restore it the early increment that nf_tables_newsetelem() performs. Fixes: c016c7e45ddf ("netfilter: nf_tables: honor NLM_F_EXCL flag in set element insertion") Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx> --- net/netfilter/nf_tables_api.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 091d2dcc63b2..a4619cbf2fe2 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -3734,8 +3734,10 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set, nft_set_ext_exists(ext2, NFT_SET_EXT_OBJREF) && *nft_set_ext_obj(ext) != *nft_set_ext_obj(ext2))) err = -EBUSY; - else if (!(nlmsg_flags & NLM_F_EXCL)) + else if (!(nlmsg_flags & NLM_F_EXCL)) { + atomic_dec(&set->nelems); err = 0; + } } goto err5; } -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html