Commit fcbebb8e authored by Ziyang Xuan's avatar Ziyang Xuan
Browse files

netfilter: nf_tables: Fix potential data-race in __nft_obj_type_get() 

mainline inclusion
from mainline-v6.9-rc5
commit d78d867dcea69c328db30df665be5be7d0148484
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9L4T1
CVE: CVE-2024-27019

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=d78d867dcea69c328db30df665be5be7d0148484



--------------------------------

nft_unregister_obj() can concurrent with __nft_obj_type_get(),
and there is not any protection when iterate over nf_tables_objects
list in __nft_obj_type_get(). Therefore, there is potential data-race
of nf_tables_objects list entry.

Use list_for_each_entry_rcu() to iterate over nf_tables_objects
list in __nft_obj_type_get(), and use rcu_read_lock() in the caller
nft_obj_type_get() to protect the entire type query process.

Fixes: e5009240 ("netfilter: nf_tables: add stateful objects")
Signed-off-by: default avatarZiyang Xuan <william.xuanziyang@huawei.com>
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
Conflicts:
	net/netfilter/nf_tables_api.c
[The version does not include 776d45164844.]
Signed-off-by: default avatarZiyang Xuan <william.xuanziyang@huawei.com>
parent 7d91c9c7

net/netfilter/nf_tables_api.c

+6 −2
Original line number Diff line number Diff line
@@ -5066,7 +5066,7 @@ static const struct nft_object_type *__nft_obj_type_get(u32 objtype) 
{

	const struct nft_object_type *type;



	list_for_each_entry(type, &nf_tables_objects, list) {

	list_for_each_entry_rcu(type, &nf_tables_objects, list) {

		if (objtype == type->type)

			return type;

	}
@@ -5078,9 +5078,13 @@ nft_obj_type_get(struct net *net, u32 objtype) 
{

	const struct nft_object_type *type;



	rcu_read_lock();

	type = __nft_obj_type_get(objtype);

	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