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=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham 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 4A680C64E7B for ; Tue, 17 Nov 2020 13:32:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0BC372168B for ; Tue, 17 Nov 2020 13:32:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="fJQrohkb" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732239AbgKQNcH (ORCPT ); Tue, 17 Nov 2020 08:32:07 -0500 Received: from mail.kernel.org ([198.145.29.99]:41488 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731540AbgKQNcG (ORCPT ); Tue, 17 Nov 2020 08:32:06 -0500 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E55B8207BC; Tue, 17 Nov 2020 13:32:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1605619926; bh=U5ILUUZszFVgPDcqDtYOt4f9Ux+iVgLzLZO2zPJ9aG0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fJQrohkb/BfVm0mJzUVwBUZEbSQxrDBCH7xcAoggHkHnYVksPR6t9eS7y9vGMRJv4 SG5YA8hLSn41qhOEHK19HHZahdjTWxUyNyO468AEZBlwIlpcPjoaSOXRR8nHXcZ+0r RKB/v/xqulIy4hbYlq9pr/NKO+JmUQeqzNPQxh6A= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Zhang Changzhong , Oleksij Rempel , Marc Kleine-Budde , Sasha Levin Subject: [PATCH 5.9 050/255] can: j1939: j1939_sk_bind(): return failure if netdev is down Date: Tue, 17 Nov 2020 14:03:10 +0100 Message-Id: <20201117122141.386940561@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201117122138.925150709@linuxfoundation.org> References: <20201117122138.925150709@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: stable@vger.kernel.org From: Zhang Changzhong [ Upstream commit 08c487d8d807535f509ed80c6a10ad90e6872139 ] When a netdev down event occurs after a successful call to j1939_sk_bind(), j1939_netdev_notify() can handle it correctly. But if the netdev already in down state before calling j1939_sk_bind(), j1939_sk_release() will stay in wait_event_interruptible() blocked forever. Because in this case, j1939_netdev_notify() won't be called and j1939_tp_txtimer() won't call j1939_session_cancel() or other function to clear session for ENETDOWN error, this lead to mismatch of j1939_session_get/put() and jsk->skb_pending will never decrease to zero. To reproduce it use following commands: 1. ip link add dev vcan0 type vcan 2. j1939acd -r 100,80-120 1122334455667788 vcan0 3. presses ctrl-c and thread will be blocked forever This patch adds check for ndev->flags in j1939_sk_bind() to avoid this kind of situation and return with -ENETDOWN. Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol") Signed-off-by: Zhang Changzhong Link: https://lore.kernel.org/r/1599460308-18770-1-git-send-email-zhangchangzhong@huawei.com Acked-by: Oleksij Rempel Signed-off-by: Marc Kleine-Budde Signed-off-by: Sasha Levin --- net/can/j1939/socket.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/net/can/j1939/socket.c b/net/can/j1939/socket.c index 1be4c898b2fa8..f23966526a885 100644 --- a/net/can/j1939/socket.c +++ b/net/can/j1939/socket.c @@ -475,6 +475,12 @@ static int j1939_sk_bind(struct socket *sock, struct sockaddr *uaddr, int len) goto out_release_sock; } + if (!(ndev->flags & IFF_UP)) { + dev_put(ndev); + ret = -ENETDOWN; + goto out_release_sock; + } + priv = j1939_netdev_start(ndev); dev_put(ndev); if (IS_ERR(priv)) { -- 2.27.0