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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,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 2B201C07E9C for ; Mon, 12 Jul 2021 06:38:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 20624610F7 for ; Mon, 12 Jul 2021 06:38:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235932AbhGLGlb (ORCPT ); Mon, 12 Jul 2021 02:41:31 -0400 Received: from mail.kernel.org ([198.145.29.99]:55076 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233686AbhGLGdm (ORCPT ); Mon, 12 Jul 2021 02:33:42 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id D0F906113E; Mon, 12 Jul 2021 06:30:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626071401; bh=ObtccxhA6maFkNuGS8SVMVX4ToKpiiF2Cefv679MDRw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=urr+86/tbhWaTO9FY2fPH3tWUNlEwZJIYc+ehKllpQtZgwvTHdp2r0FAcwIwXgUWT jIbDRL3AIvZjHliWzh+SR8Jf2DIoy3g3SYcxtL872IUn6l9gS8UIEwQDK/THtY6KpE OBF/VqHnRNCUW9ZYwQugPmjafAAIhRql8jE4UCtw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Thadeu Lima de Souza Cascardo , syzbot+bdf710cfc41c186fdff3@syzkaller.appspotmail.com, Oleksij Rempel , Marc Kleine-Budde Subject: [PATCH 5.10 053/593] can: j1939: j1939_sk_init(): set SOCK_RCU_FREE to call sk_destruct() after RCU is done Date: Mon, 12 Jul 2021 08:03:33 +0200 Message-Id: <20210712060848.948404539@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210712060843.180606720@linuxfoundation.org> References: <20210712060843.180606720@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Oleksij Rempel commit 22c696fed25c63c7f67508309820358b94a96b6d upstream. 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 Signed-off-by: Greg Kroah-Hartman --- net/can/j1939/main.c | 4 ++++ net/can/j1939/socket.c | 3 +++ 2 files changed, 7 insertions(+) --- a/net/can/j1939/main.c +++ b/net/can/j1939/main.c @@ -193,6 +193,10 @@ static void j1939_can_rx_unregister(stru 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); } --- 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;