From: Paolo Abeni pabeni@redhat.com
commit 2c02d41d71f90a5168391b6a5f2954112ba2307c upstream.
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: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/ipv4/inet_connection_sock.c | 16 +++++++++++++++- net/ipv4/tcp_ulp.c | 4 ++++ 2 files changed, 19 insertions(+), 1 deletion(-)
--- a/net/ipv4/inet_connection_sock.c +++ b/net/ipv4/inet_connection_sock.c @@ -916,11 +916,25 @@ void inet_csk_prepare_forced_close(struc } 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, int backlog) { struct inet_connection_sock *icsk = inet_csk(sk); struct inet_sock *inet = inet_sk(sk); - int err = -EADDRINUSE; + int err; + + err = inet_ulp_can_listen(sk); + if (unlikely(err)) + return err;
reqsk_queue_alloc(&icsk->icsk_accept_queue);
--- a/net/ipv4/tcp_ulp.c +++ b/net/ipv4/tcp_ulp.c @@ -136,6 +136,10 @@ static int __tcp_set_ulp(struct sock *sk if (icsk->icsk_ulp_ops) goto out_err;
+ err = -EINVAL; + if (!ulp_ops->clone && sk->sk_state == TCP_LISTEN) + goto out_err; + err = ulp_ops->init(sk); if (err) goto out_err;