From: Paolo Abeni <pabeni@xxxxxxxxxx>
[ 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@xxxxxxxxx>
Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
Link: https://lore.kernel.org/r/4b80c3d1dbe3d0ab072f80450c202d9bc88b4b03.1672740602.git.pabeni@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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;
--
2.35.1
