Commit cf44bd08 authored by Pengcheng Yang's avatar Pengcheng Yang Committed by Jakub Kicinski
Browse files

tcp: only release congestion control if it has been initialized 



Currently, when cleaning up congestion control, we always call the
release regardless of whether it has been initialized. There is no
need to release when closing TCP_LISTEN and TCP_CLOSE (close
immediately after socket()).

In this case, tcp_cdg calls kfree(NULL) in release without causing
an exception, but for some customized ca, this could lead to
unexpected exceptions. We need to ensure that init and release are
called in pairs.

Signed-off-by: default avatarPengcheng Yang <yangpc@wangsu.com>
Link: https://patch.msgid.link/1729845944-6003-1-git-send-email-yangpc@wangsu.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 5b1c9659

net/ipv4/tcp.c

+1 −1
Original line number Diff line number Diff line
@@ -3336,7 +3336,7 @@ int tcp_disconnect(struct sock *sk, int flags) 
	tp->window_clamp = 0;

	tp->delivered = 0;

	tp->delivered_ce = 0;

	if (icsk->icsk_ca_ops->release)

	if (icsk->icsk_ca_initialized && icsk->icsk_ca_ops->release)

		icsk->icsk_ca_ops->release(sk);

	memset(icsk->icsk_ca_priv, 0, sizeof(icsk->icsk_ca_priv));

	icsk->icsk_ca_initialized = 0;

net/ipv4/tcp_cong.c

+2 −1
Original line number Diff line number Diff line
@@ -270,8 +270,9 @@ void tcp_cleanup_congestion_control(struct sock *sk) 
{

	struct inet_connection_sock *icsk = inet_csk(sk);



	if (icsk->icsk_ca_ops->release)

	if (icsk->icsk_ca_initialized && icsk->icsk_ca_ops->release)

		icsk->icsk_ca_ops->release(sk);

	icsk->icsk_ca_initialized = 0;

	bpf_module_put(icsk->icsk_ca_ops, icsk->icsk_ca_ops->owner);

}