From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7DD9AC2B9F4 for ; Sat, 19 Jun 2021 22:01:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 637CF6117A for ; Sat, 19 Jun 2021 22:01:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230332AbhFSWDt (ORCPT ); Sat, 19 Jun 2021 18:03:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37120 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230211AbhFSWDj (ORCPT ); Sat, 19 Jun 2021 18:03:39 -0400 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E8962C061768 for ; Sat, 19 Jun 2021 15:01:27 -0700 (PDT) Received: from gallifrey.ext.pengutronix.de ([2001:67c:670:201:5054:ff:fe8d:eefb] helo=bjornoya.blackshift.org) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1luj1q-0005YB-BD for netdev@vger.kernel.org; Sun, 20 Jun 2021 00:01:26 +0200 Received: from dspam.blackshift.org (localhost [127.0.0.1]) by bjornoya.blackshift.org (Postfix) with SMTP id 5ECC663F816 for ; Sat, 19 Jun 2021 22:01:23 +0000 (UTC) Received: from hardanger.blackshift.org (unknown [172.20.34.65]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-384) server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by bjornoya.blackshift.org (Postfix) with ESMTPS id 5A90763F7E7; Sat, 19 Jun 2021 22:01:19 +0000 (UTC) Received: from blackshift.org (localhost [::1]) by hardanger.blackshift.org (OpenSMTPD) with ESMTP id bf06fd0f; Sat, 19 Jun 2021 22:01:18 +0000 (UTC) From: Marc Kleine-Budde To: netdev@vger.kernel.org Cc: davem@davemloft.net, kuba@kernel.org, linux-can@vger.kernel.org, kernel@pengutronix.de, Oleksij Rempel , linux-stable , Thadeu Lima de Souza Cascardo , syzbot+bdf710cfc41c186fdff3@syzkaller.appspotmail.com, Marc Kleine-Budde Subject: [net 4/5] can: j1939: j1939_sk_init(): set SOCK_RCU_FREE to call sk_destruct() after RCU is done Date: Sun, 20 Jun 2021 00:01:14 +0200 Message-Id: <20210619220115.2830761-5-mkl@pengutronix.de> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210619220115.2830761-1-mkl@pengutronix.de> References: <20210619220115.2830761-1-mkl@pengutronix.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 2001:67c:670:201:5054:ff:fe8d:eefb X-SA-Exim-Mail-From: mkl@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: netdev@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Oleksij Rempel Set SOCK_RCU_FREE to let RCU to call sk_destruct() on completion. Without this patch, we will run in to j1939_can_recv() after priv was freed by j1939_sk_release()->j1939_sk_sock_destruct() Fixes: 25fe97cb7620 ("can: j1939: move j1939_priv_put() into sk_destruct callback") Link: https://lore.kernel.org/r/20210617130623.12705-1-o.rempel@pengutronix.de Cc: linux-stable Reported-by: Thadeu Lima de Souza Cascardo Reported-by: syzbot+bdf710cfc41c186fdff3@syzkaller.appspotmail.com Signed-off-by: Oleksij Rempel Signed-off-by: Marc Kleine-Budde --- net/can/j1939/main.c | 4 ++++ net/can/j1939/socket.c | 3 +++ 2 files changed, 7 insertions(+) diff --git a/net/can/j1939/main.c b/net/can/j1939/main.c index da3a7a7bcff2..08c8606cfd9c 100644 --- a/net/can/j1939/main.c +++ b/net/can/j1939/main.c @@ -193,6 +193,10 @@ static void j1939_can_rx_unregister(struct j1939_priv *priv) can_rx_unregister(dev_net(ndev), ndev, J1939_CAN_ID, J1939_CAN_MASK, j1939_can_recv, priv); + /* The last reference of priv is dropped by the RCU deferred + * j1939_sk_sock_destruct() of the last socket, so we can + * safely drop this reference here. + */ j1939_priv_put(priv); } diff --git a/net/can/j1939/socket.c b/net/can/j1939/socket.c index 56aa66147d5a..fce8bc8afeb7 100644 --- a/net/can/j1939/socket.c +++ b/net/can/j1939/socket.c @@ -398,6 +398,9 @@ static int j1939_sk_init(struct sock *sk) atomic_set(&jsk->skb_pending, 0); spin_lock_init(&jsk->sk_session_queue_lock); INIT_LIST_HEAD(&jsk->sk_session_queue); + + /* j1939_sk_sock_destruct() depends on SOCK_RCU_FREE flag */ + sock_set_flag(sk, SOCK_RCU_FREE); sk->sk_destruct = j1939_sk_sock_destruct; sk->sk_protocol = CAN_J1939; -- 2.30.2