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net/ulp: prevent ULP without clone op from entering the LISTEN status

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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: 734942cc4e ("tcp: ULP infrastructure")
Reported-by: slipper <slipper.alive@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/4b80c3d1dbe3d0ab072f80450c202d9bc88b4b03.1672740602.git.pabeni@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Paolo Abeni 2023-01-03 12:19:17 +01:00 committed by Jakub Kicinski
parent 5401c3e099
commit 2c02d41d71
2 changed files with 18 additions and 0 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

14
net/ipv4/inet_connection_sock.c
View file

@ -1200,12 +1200,26 @@ void inet_csk_prepare_forced_close(struct sock *sk)
} }
EXPORT_SYMBOL(inet_csk_prepare_forced_close); 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 inet_csk_listen_start(struct sock *sk)
{ {
struct inet_connection_sock *icsk = inet_csk(sk); struct inet_connection_sock *icsk = inet_csk(sk);
struct inet_sock *inet = inet_sk(sk); struct inet_sock *inet = inet_sk(sk);
int err; int err;
err = inet_ulp_can_listen(sk);
if (unlikely(err))
return err;
reqsk_queue_alloc(&icsk->icsk_accept_queue); reqsk_queue_alloc(&icsk->icsk_accept_queue);
sk->sk_ack_backlog = 0; sk->sk_ack_backlog = 0;

4
net/ipv4/tcp_ulp.c
View file

@ -139,6 +139,10 @@ static int __tcp_set_ulp(struct sock *sk, const struct tcp_ulp_ops *ulp_ops)
if (sk->sk_socket) if (sk->sk_socket)
clear_bit(SOCK_SUPPORT_ZC, &sk->sk_socket->flags); 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); err = ulp_ops->init(sk);
if (err) if (err)
goto out_err; goto out_err;