From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A20096FA1 for ; Mon, 3 Apr 2023 14:40:52 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 274C7C433D2; Mon, 3 Apr 2023 14:40:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1680532852; bh=lqCj2IrxJRiHvfJNpW0pIk9HAiPYPcQsC53d06/2DPU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eLSkY42r/aGUqU4hqIw1t1arcFCXGYb1GW7pHeSQsdm7iuYdNM/IyVZ69Vjt1l88p yJmfise+aWLcbE1Az9beMa8n26RfcZKTdO6ZYXlxQcSsYBS+vLZNgxfDk9vvbWR9RJ ECvH/NfNM7e9Ahxk2BEYZ+ktmEuu6DMf1+9VZM/k= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+ee1cd780f69483a8616b@syzkaller.appspotmail.com, Hillf Danton , Oleksij Rempel , Marc Kleine-Budde Subject: [PATCH 6.1 141/181] can: j1939: prevent deadlock by moving j1939_sk_errqueue() Date: Mon, 3 Apr 2023 16:09:36 +0200 Message-Id: <20230403140419.645148905@linuxfoundation.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230403140415.090615502@linuxfoundation.org> References: <20230403140415.090615502@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Oleksij Rempel commit d1366b283d94ac4537a4b3a1e8668da4df7ce7e9 upstream. This commit addresses a deadlock situation that can occur in certain scenarios, such as when running data TP/ETP transfer and subscribing to the error queue while receiving a net down event. The deadlock involves locks in the following order: 3 j1939_session_list_lock -> active_session_list_lock j1939_session_activate ... j1939_sk_queue_activate_next -> sk_session_queue_lock ... j1939_xtp_rx_eoma_one 2 j1939_sk_queue_drop_all -> sk_session_queue_lock ... j1939_sk_netdev_event_netdown -> j1939_socks_lock j1939_netdev_notify 1 j1939_sk_errqueue -> j1939_socks_lock __j1939_session_cancel -> active_session_list_lock j1939_tp_rxtimer CPU0 CPU1 ---- ---- lock(&priv->active_session_list_lock); lock(&jsk->sk_session_queue_lock); lock(&priv->active_session_list_lock); lock(&priv->j1939_socks_lock); The solution implemented in this commit is to move the j1939_sk_errqueue() call out of the active_session_list_lock context, thus preventing the deadlock situation. Reported-by: syzbot+ee1cd780f69483a8616b@syzkaller.appspotmail.com Fixes: 5b9272e93f2e ("can: j1939: extend UAPI to notify about RX status") Co-developed-by: Hillf Danton Signed-off-by: Hillf Danton Signed-off-by: Oleksij Rempel Link: https://lore.kernel.org/all/20230324130141.2132787-1-o.rempel@pengutronix.de Cc: stable@vger.kernel.org Signed-off-by: Marc Kleine-Budde Signed-off-by: Greg Kroah-Hartman --- net/can/j1939/transport.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) --- a/net/can/j1939/transport.c +++ b/net/can/j1939/transport.c @@ -1124,8 +1124,6 @@ static void __j1939_session_cancel(struc if (session->sk) j1939_sk_send_loop_abort(session->sk, session->err); - else - j1939_sk_errqueue(session, J1939_ERRQUEUE_RX_ABORT); } static void j1939_session_cancel(struct j1939_session *session, @@ -1140,6 +1138,9 @@ static void j1939_session_cancel(struct } j1939_session_list_unlock(session->priv); + + if (!session->sk) + j1939_sk_errqueue(session, J1939_ERRQUEUE_RX_ABORT); } static enum hrtimer_restart j1939_tp_txtimer(struct hrtimer *hrtimer) @@ -1253,6 +1254,9 @@ static enum hrtimer_restart j1939_tp_rxt __j1939_session_cancel(session, J1939_XTP_ABORT_TIMEOUT); } j1939_session_list_unlock(session->priv); + + if (!session->sk) + j1939_sk_errqueue(session, J1939_ERRQUEUE_RX_ABORT); } j1939_session_put(session);