| Message ID | ab7c6584a047d80a9c4658a4d196b555567642e4.1712472595.git.william.xuanziyang@huawei.com |
|---|---|
| State | Accepted |
| Headers | show |
| Series | netfilter: nf_tables: Use rcu lock to enhance protection of the lists | expand |
On Sun, Apr 07, 2024 at 02:56:05PM +0800, Ziyang Xuan wrote: > 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 pertential > 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. Also applied, thanks > Fixes: e50092404c1b ("netfilter: nf_tables: add stateful objects") > Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com> > --- > 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 646d59685cfd..70fe0ca24d34 100644 > --- a/net/netfilter/nf_tables_api.c > +++ b/net/netfilter/nf_tables_api.c > @@ -7607,7 +7607,7 @@ static const struct nft_object_type *__nft_obj_type_get(u32 objtype, u8 family) > { > 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 (type->family != NFPROTO_UNSPEC && > type->family != family) > continue; > @@ -7623,9 +7623,13 @@ nft_obj_type_get(struct net *net, u32 objtype, u8 family) > { > const struct nft_object_type *type; > > + rcu_read_lock(); > type = __nft_obj_type_get(objtype, family); > - 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 > -- > 2.25.1 >
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 646d59685cfd..70fe0ca24d34 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -7607,7 +7607,7 @@ static const struct nft_object_type *__nft_obj_type_get(u32 objtype, u8 family) { 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 (type->family != NFPROTO_UNSPEC && type->family != family) continue; @@ -7623,9 +7623,13 @@ nft_obj_type_get(struct net *net, u32 objtype, u8 family) { const struct nft_object_type *type; + rcu_read_lock(); type = __nft_obj_type_get(objtype, family); - 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
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 pertential 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: e50092404c1b ("netfilter: nf_tables: add stateful objects") Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com> --- net/netfilter/nf_tables_api.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)