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=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 61F38C838FC for ; Tue, 27 Oct 2020 15:56:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1A6EB204EF for ; Tue, 27 Oct 2020 15:56:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603814217; bh=W+K7W4+QGo782brgjmLPUIo3oVKY6jD0sJmTUqB5PVM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=EGfw+QQ7v5BSF4xPlSlIhk9C529ki/BqYDdv6x1Mn0YJdsjfE7qU7ri82X5PCI1VJ 9fig/7LPMfeBAQ2DHUz+tzjxKwZ2Bb+J16XOewuCDV7w72QBp4Q002v/2Zosa11Guj ZH9WwV1pJCEyQdPLzet25AqA+gC/zIoFdmkf4fds= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1803634AbgJ0PxM (ORCPT ); Tue, 27 Oct 2020 11:53:12 -0400 Received: from mail.kernel.org ([198.145.29.99]:44324 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1798505AbgJ0P2Y (ORCPT ); Tue, 27 Oct 2020 11:28:24 -0400 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 CA55A2064B; Tue, 27 Oct 2020 15:28:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603812503; bh=W+K7W4+QGo782brgjmLPUIo3oVKY6jD0sJmTUqB5PVM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OjPU1ocW/MmzP3Pp6TYC7dq8iC1+8xemBVojOW1fCJHdzy/zFrUPuGRmxLqHtjzmw FDieoLstfad4bdVk+mY79g/wKuyCob4WYAeTjp3FHExSciek6c2+96PrleD+wToaQF LfLqgGbTx8p5B5+LAAwLgNfeedRpwGhxM1hEXauc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Tyrel Datwyler , Sasha Levin Subject: [PATCH 5.9 232/757] tty: hvcs: Dont NULL tty->driver_data until hvcs_cleanup() Date: Tue, 27 Oct 2020 14:48:02 +0100 Message-Id: <20201027135501.488886858@linuxfoundation.org> X-Mailer: git-send-email 2.29.1 In-Reply-To: <20201027135450.497324313@linuxfoundation.org> References: <20201027135450.497324313@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: Tyrel Datwyler [ Upstream commit 63ffcbdad738e3d1c857027789a2273df3337624 ] The code currently NULLs tty->driver_data in hvcs_close() with the intent of informing the next call to hvcs_open() that device needs to be reconfigured. However, when hvcs_cleanup() is called we copy hvcsd from tty->driver_data which was previoulsy NULLed by hvcs_close() and our call to tty_port_put(&hvcsd->port) doesn't actually do anything since &hvcsd->port ends up translating to NULL by chance. This has the side effect that when hvcs_remove() is called we have one too many port references preventing hvcs_destuct_port() from ever being called. This also prevents us from reusing the /dev/hvcsX node in a future hvcs_probe() and we can eventually run out of /dev/hvcsX devices. Fix this by waiting to NULL tty->driver_data in hvcs_cleanup(). Fixes: 27bf7c43a19c ("TTY: hvcs, add tty install") Signed-off-by: Tyrel Datwyler Link: https://lore.kernel.org/r/20200820234643.70412-1-tyreld@linux.ibm.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/tty/hvc/hvcs.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/drivers/tty/hvc/hvcs.c b/drivers/tty/hvc/hvcs.c index 55105ac38f89b..509d1042825a1 100644 --- a/drivers/tty/hvc/hvcs.c +++ b/drivers/tty/hvc/hvcs.c @@ -1216,13 +1216,6 @@ static void hvcs_close(struct tty_struct *tty, struct file *filp) tty_wait_until_sent(tty, HVCS_CLOSE_WAIT); - /* - * This line is important because it tells hvcs_open that this - * device needs to be re-configured the next time hvcs_open is - * called. - */ - tty->driver_data = NULL; - free_irq(irq, hvcsd); return; } else if (hvcsd->port.count < 0) { @@ -1237,6 +1230,13 @@ static void hvcs_cleanup(struct tty_struct * tty) { struct hvcs_struct *hvcsd = tty->driver_data; + /* + * This line is important because it tells hvcs_open that this + * device needs to be re-configured the next time hvcs_open is + * called. + */ + tty->driver_data = NULL; + tty_port_put(&hvcsd->port); } -- 2.25.1