From: Paolo Abeni pabeni@redhat.com
[ Upstream commit 2c02d41d71f90a5168391b6a5f2954112ba2307c ]
When an ULP-enabled socket enters the LISTEN status, the listener ULP data pointer is copied inside the child/accepted sockets by sk_clone_lock().
The relevant ULP can take care of de-duplicating the context pointer via the clone() operation, but only MPTCP and SMC implement such op.
Other ULPs may end-up with a double-free at socket disposal time.
We can't simply clear the ULP data at clone time, as TLS replaces the socket ops with custom ones assuming a valid TLS ULP context is available.
Instead completely prevent clone-less ULP sockets from entering the LISTEN status.
Fixes: 734942cc4ea6 ("tcp: ULP infrastructure") Reported-by: slipper slipper.alive@gmail.com Signed-off-by: Paolo Abeni pabeni@redhat.com Link: https://lore.kernel.org/r/4b80c3d1dbe3d0ab072f80450c202d9bc88b4b03.167274060... Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- net/ipv4/inet_connection_sock.c | 14 ++++++++++++++ net/ipv4/tcp_ulp.c | 4 ++++ 2 files changed, 18 insertions(+)
diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c index 0465ada82799..647b3c6b575e 100644 --- a/net/ipv4/inet_connection_sock.c +++ b/net/ipv4/inet_connection_sock.c @@ -1200,12 +1200,26 @@ void inet_csk_prepare_forced_close(struct sock *sk) } EXPORT_SYMBOL(inet_csk_prepare_forced_close);
+static int inet_ulp_can_listen(const struct sock *sk) +{ + const struct inet_connection_sock *icsk = inet_csk(sk); + + if (icsk->icsk_ulp_ops && !icsk->icsk_ulp_ops->clone) + return -EINVAL; + + return 0; +} + int inet_csk_listen_start(struct sock *sk) { struct inet_connection_sock *icsk = inet_csk(sk); struct inet_sock *inet = inet_sk(sk); int err;
+ err = inet_ulp_can_listen(sk); + if (unlikely(err)) + return err; + reqsk_queue_alloc(&icsk->icsk_accept_queue);
sk->sk_ack_backlog = 0; diff --git a/net/ipv4/tcp_ulp.c b/net/ipv4/tcp_ulp.c index 9ae50b1bd844..05b6077b9f2c 100644 --- a/net/ipv4/tcp_ulp.c +++ b/net/ipv4/tcp_ulp.c @@ -139,6 +139,10 @@ static int __tcp_set_ulp(struct sock *sk, const struct tcp_ulp_ops *ulp_ops) if (sk->sk_socket) clear_bit(SOCK_SUPPORT_ZC, &sk->sk_socket->flags);
+ err = -EINVAL; + if (!ulp_ops->clone && sk->sk_state == TCP_LISTEN) + goto out_err; + err = ulp_ops->init(sk); if (err) goto out_err;