Re: [PATCH 4.19 stable 2/5] Backport netfilter: nf_tables: autoload modules from the abort path

[Amy Fong <Amy_Fong@mentor.com>]

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