diff options
Diffstat (limited to 'queue-4.19/netfilter-nf_tables-fix-potential-data-race-in-__nft.patch')
| -rw-r--r-- | queue-4.19/netfilter-nf_tables-fix-potential-data-race-in-__nft.patch | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/queue-4.19/netfilter-nf_tables-fix-potential-data-race-in-__nft.patch b/queue-4.19/netfilter-nf_tables-fix-potential-data-race-in-__nft.patch new file mode 100644 index 0000000000..32de701805 --- /dev/null +++ b/queue-4.19/netfilter-nf_tables-fix-potential-data-race-in-__nft.patch @@ -0,0 +1,58 @@ +From ca4d6a0ef77a0c435235ad011b049a777ece97e9 Mon Sep 17 00:00:00 2001 +From: Sasha Levin <sashal@kernel.org> +Date: Sun, 7 Apr 2024 14:56:04 +0800 +Subject: netfilter: nf_tables: Fix potential data-race in + __nft_expr_type_get() + +From: Ziyang Xuan <william.xuanziyang@huawei.com> + +[ Upstream commit f969eb84ce482331a991079ab7a5c4dc3b7f89bf ] + +nft_unregister_expr() can concurrent with __nft_expr_type_get(), +and there is not any protection when iterate over nf_tables_expressions +list in __nft_expr_type_get(). Therefore, there is potential data-race +of nf_tables_expressions list entry. + +Use list_for_each_entry_rcu() to iterate over nf_tables_expressions +list in __nft_expr_type_get(), and use rcu_read_lock() in the caller +nft_expr_type_get() to protect the entire type query process. + +Fixes: ef1f7df9170d ("netfilter: nf_tables: expression ops overloading") +Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com> +Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> +Signed-off-by: Sasha Levin <sashal@kernel.org> +--- + net/netfilter/nf_tables_api.c | 8 ++++++-- + 1 file changed, 6 insertions(+), 2 deletions(-) + +diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c +index 79d0545badcab..db453d19f2a0f 100644 +--- a/net/netfilter/nf_tables_api.c ++++ b/net/netfilter/nf_tables_api.c +@@ -2083,7 +2083,7 @@ static const struct nft_expr_type *__nft_expr_type_get(u8 family, + { + const struct nft_expr_type *type, *candidate = NULL; + +- list_for_each_entry(type, &nf_tables_expressions, list) { ++ list_for_each_entry_rcu(type, &nf_tables_expressions, list) { + if (!nla_strcmp(nla, type->name)) { + if (!type->family && !candidate) + candidate = type; +@@ -2103,9 +2103,13 @@ static const struct nft_expr_type *nft_expr_type_get(struct net *net, + if (nla == NULL) + return ERR_PTR(-EINVAL); + ++ rcu_read_lock(); + type = __nft_expr_type_get(family, nla); +- if (type != NULL && try_module_get(type->owner)) ++ if (type != NULL && try_module_get(type->owner)) { ++ rcu_read_unlock(); + return type; ++ } ++ rcu_read_unlock(); + + lockdep_nfnl_nft_mutex_not_held(); + #ifdef CONFIG_MODULES +-- +2.43.0 + |