From 2c02d41d71f90a5168391b6a5f2954112ba2307c Mon Sep 17 00:00:00 2001 From: Paolo Abeni Date: Tue, 3 Jan 2023 12:19:17 +0100 Subject: net/ulp: prevent ULP without clone op from entering the LISTEN status 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 Signed-off-by: Paolo Abeni Link: https://lore.kernel.org/r/4b80c3d1dbe3d0ab072f80450c202d9bc88b4b03.1672740602.git.pabeni@redhat.com Signed-off-by: Jakub Kicinski --- net/ipv4/tcp_ulp.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'net/ipv4/tcp_ulp.c') 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; -- cgit v1.2.3