Re: [cip-dev] [PATCH 4.19.y-cip 2/6] Backport netfilter: nf_tables: autoload modules from the abort path

Amy Fong
2022-01-10T14:12:15Z

From 185a61df95c18e5111df5ba439b0e60a8a6e40cb Mon Sep 17 00:00:00 2001
From: Pablo Neira Ayuso <pablo@netfilter.org>
Date: Fri, 5 Jul 2019 23:38:46 +0200
Subject: [PATCH 2/5] netfilter: nf_tables: add nft_expr_type_request_module()

This helper function makes sure the family specific extension is loaded.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
(cherry picked from commit b9c04ae7907f09c5e873e7c9a8feea2ce41e15b3)
---
net/netfilter/nf_tables_api.c | 17 ++++++++++++++---
1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 02e577e8fb8a..8ec38de1f7a1 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -2009,6 +2009,19 @@ static const struct nft_expr_type *__nft_expr_type_get(u8 family,
return NULL;
}

+#ifdef CONFIG_MODULES
+static int nft_expr_type_request_module(struct net *net, u8 family,
+ struct nlattr *nla)
+{
+ nft_request_module(net, "nft-expr-%u-%.*s", family,
+ nla_len(nla), (char *)nla_data(nla));
+ if (__nft_expr_type_get(family, nla))
+ return -EAGAIN;
+
+ return 0;
+}
+#endif
+
static const struct nft_expr_type *nft_expr_type_get(struct net *net,
u8 family,
struct nlattr *nla)
@@ -2025,9 +2038,7 @@ static const struct nft_expr_type *nft_expr_type_get(struct net *net,
lockdep_nfnl_nft_mutex_not_held();
#ifdef CONFIG_MODULES
if (type == NULL) {
- nft_request_module(net, "nft-expr-%u-%.*s", family,
- nla_len(nla), (char *)nla_data(nla));
- if (__nft_expr_type_get(family, nla))
+ if (nft_expr_type_request_module(net, family, nla) == -EAGAIN)
return ERR_PTR(-EAGAIN);

nft_request_module(net, "nft-expr-%.*s",
--
2.34.1