| Message ID | ZiYu9NJ/ClR8uSkH@v4bel-B760M-AORUS-ELITE-AX (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 80e679b352c3ce5158f3f778cfb77eb767e586fb |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | tcp: Fix Use-After-Free in tcp_ao_connect_init | expand |
On Mon, Apr 22, 2024 at 11:33 AM Hyunwoo Kim <v4bel@theori.io> wrote: > > Since call_rcu, which is called in the hlist_for_each_entry_rcu traversal > of tcp_ao_connect_init, is not part of the RCU read critical section, it > is possible that the RCU grace period will pass during the traversal and > the key will be free. > > To prevent this, it should be changed to hlist_for_each_entry_safe. > > Fixes: 7c2ffaf21bd6 ("net/tcp: Calculate TCP-AO traffic keys") > Signed-off-by: Hyunwoo Kim <v4bel@theori.io> > --- Reviewed-by: Eric Dumazet <edumazet@google.com> Thanks !
On Mon, 22 Apr 2024 at 10:33, Hyunwoo Kim <v4bel@theori.io> wrote: > > Since call_rcu, which is called in the hlist_for_each_entry_rcu traversal > of tcp_ao_connect_init, is not part of the RCU read critical section, it > is possible that the RCU grace period will pass during the traversal and > the key will be free. > > To prevent this, it should be changed to hlist_for_each_entry_safe. > > Fixes: 7c2ffaf21bd6 ("net/tcp: Calculate TCP-AO traffic keys") > Signed-off-by: Hyunwoo Kim <v4bel@theori.io> Thank you, Acked-by: Dmitry Safonov <0x7f454c46@gmail.com> > --- > net/ipv4/tcp_ao.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/net/ipv4/tcp_ao.c b/net/ipv4/tcp_ao.c > index 3afeeb68e8a7..781b67a52571 100644 > --- a/net/ipv4/tcp_ao.c > +++ b/net/ipv4/tcp_ao.c > @@ -1068,6 +1068,7 @@ void tcp_ao_connect_init(struct sock *sk) > { > struct tcp_sock *tp = tcp_sk(sk); > struct tcp_ao_info *ao_info; > + struct hlist_node *next; > union tcp_ao_addr *addr; > struct tcp_ao_key *key; > int family, l3index; > @@ -1090,7 +1091,7 @@ void tcp_ao_connect_init(struct sock *sk) > l3index = l3mdev_master_ifindex_by_index(sock_net(sk), > sk->sk_bound_dev_if); > > - hlist_for_each_entry_rcu(key, &ao_info->head, node) { > + hlist_for_each_entry_safe(key, next, &ao_info->head, node) { > if (!tcp_ao_key_cmp(key, l3index, addr, key->prefixlen, family, -1, -1)) > continue; > > -- > 2.34.1 > -- Dmitry
Hello: This patch was applied to netdev/net.git (main) by Jakub Kicinski <kuba@kernel.org>: On Mon, 22 Apr 2024 05:33:40 -0400 you wrote: > Since call_rcu, which is called in the hlist_for_each_entry_rcu traversal > of tcp_ao_connect_init, is not part of the RCU read critical section, it > is possible that the RCU grace period will pass during the traversal and > the key will be free. > > To prevent this, it should be changed to hlist_for_each_entry_safe. > > [...] Here is the summary with links: - tcp: Fix Use-After-Free in tcp_ao_connect_init https://git.kernel.org/netdev/net/c/80e679b352c3 You are awesome, thank you!
diff --git a/net/ipv4/tcp_ao.c b/net/ipv4/tcp_ao.c index 3afeeb68e8a7..781b67a52571 100644 --- a/net/ipv4/tcp_ao.c +++ b/net/ipv4/tcp_ao.c @@ -1068,6 +1068,7 @@ void tcp_ao_connect_init(struct sock *sk) { struct tcp_sock *tp = tcp_sk(sk); struct tcp_ao_info *ao_info; + struct hlist_node *next; union tcp_ao_addr *addr; struct tcp_ao_key *key; int family, l3index; @@ -1090,7 +1091,7 @@ void tcp_ao_connect_init(struct sock *sk) l3index = l3mdev_master_ifindex_by_index(sock_net(sk), sk->sk_bound_dev_if); - hlist_for_each_entry_rcu(key, &ao_info->head, node) { + hlist_for_each_entry_safe(key, next, &ao_info->head, node) { if (!tcp_ao_key_cmp(key, l3index, addr, key->prefixlen, family, -1, -1)) continue;
Since call_rcu, which is called in the hlist_for_each_entry_rcu traversal of tcp_ao_connect_init, is not part of the RCU read critical section, it is possible that the RCU grace period will pass during the traversal and the key will be free. To prevent this, it should be changed to hlist_for_each_entry_safe. Fixes: 7c2ffaf21bd6 ("net/tcp: Calculate TCP-AO traffic keys") Signed-off-by: Hyunwoo Kim <v4bel@theori.io> --- net/ipv4/tcp_ao.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)