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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=no 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 AC9D0C43603 for ; Tue, 17 Dec 2019 00:57:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7ACD324679 for ; Tue, 17 Dec 2019 00:57:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727698AbfLQA5r (ORCPT ); Mon, 16 Dec 2019 19:57:47 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:34940 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726808AbfLQAvk (ORCPT ); Mon, 16 Dec 2019 19:51:40 -0500 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1ih15H-0003Ku-KI; Tue, 17 Dec 2019 00:51:31 +0000 Received: from ben by deadeye with local (Exim 4.93-RC7) (envelope-from ) id 1ih15G-0005UF-Kd; Tue, 17 Dec 2019 00:51:30 +0000 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "Greg Kroah-Hartman" , "Peter Korsgaard" , "Randy Dunlap" Date: Tue, 17 Dec 2019 00:46:11 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 037/136] serial: uartlite: fix exit path null pointer In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.80-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Randy Dunlap commit a553add0846f355a28ed4e81134012e4a1e280c2 upstream. Call uart_unregister_driver() conditionally instead of unconditionally, only if it has been previously registered. This uses driver.state, just as the sh-sci.c driver does. Fixes this null pointer dereference in tty_unregister_driver(), since the 'driver' argument is null: general protection fault: 0000 [#1] PREEMPT SMP KASAN PTI RIP: 0010:tty_unregister_driver+0x25/0x1d0 Fixes: 238b8721a554 ("[PATCH] serial uartlite driver") Signed-off-by: Randy Dunlap Cc: Peter Korsgaard Link: https://lore.kernel.org/r/9c8e6581-6fcc-a595-0897-4d90f5d710df@infradead.org Signed-off-by: Greg Kroah-Hartman Signed-off-by: Ben Hutchings --- drivers/tty/serial/uartlite.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/tty/serial/uartlite.c +++ b/drivers/tty/serial/uartlite.c @@ -708,7 +708,8 @@ err_uart: static void __exit ulite_exit(void) { platform_driver_unregister(&ulite_platform_driver); - uart_unregister_driver(&ulite_uart_driver); + if (ulite_uart_driver.state) + uart_unregister_driver(&ulite_uart_driver); } module_init(ulite_init);