From cf44bd08cdeeeceb61a439f9dc437ded23adb75d Mon Sep 17 00:00:00 2001 From: Pengcheng Yang Date: Fri, 25 Oct 2024 16:45:44 +0800 Subject: 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: Pengcheng Yang Link: https://patch.msgid.link/1729845944-6003-1-git-send-email-yangpc@wangsu.com Signed-off-by: Jakub Kicinski --- net/ipv4/tcp.c | 2 +- net/ipv4/tcp_cong.c | 3 ++- 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 82cc4a5633ce..0d704bda6c41 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -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; diff --git a/net/ipv4/tcp_cong.c b/net/ipv4/tcp_cong.c index 0306d257fa64..df758adbb445 100644 --- a/net/ipv4/tcp_cong.c +++ b/net/ipv4/tcp_cong.c @@ -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); } -- cgit v1.2.3