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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,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 2F95EECE599 for ; Wed, 16 Oct 2019 22:22:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EDB24207FF for ; Wed, 16 Oct 2019 22:22:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1571264522; bh=Bf+ER69cBxaSgSskm14ZAD6nSzKcf7naYP/B+3ZIYU8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=sGf+sjtrnxU9LJG6GruSZqIH5qekDn9Q6rZAksXJvWfMkcDQBFuxRTDzgipAYt7yK SBMb26+a6geuoIujCYQt/oG7ATx1Jn+9mPD8Smkh9BvhF2BxioJXDpPpRY/SvHGcSV 6TG1w5lSXYrL0PKZNAvMm6hTWnxvtUv5m6XPpBak= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2439402AbfJPWWA (ORCPT ); Wed, 16 Oct 2019 18:22:00 -0400 Received: from mail.kernel.org ([198.145.29.99]:42306 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2394858AbfJPVx0 (ORCPT ); Wed, 16 Oct 2019 17:53:26 -0400 Received: from localhost (unknown [192.55.54.58]) (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 30F7721925; Wed, 16 Oct 2019 21:53:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1571262806; bh=Bf+ER69cBxaSgSskm14ZAD6nSzKcf7naYP/B+3ZIYU8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ag92/JOGMWolXSIdPiD8z0PbLPAcMoVj3Ep7ofrlQLA7BbrQ+EGsNFwxjTGSj7KKw 4WbLElfyhXTVxGs6AVi6AAeRR+SvaMhL7xLVpgz690iHOgBXmLtDJFifrQe33y1SEc OM6bZUp4LV9jf73xnzS9DHaYZfGnYNyva+7KNaaY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Randy Dunlap , Peter Korsgaard Subject: [PATCH 4.4 48/79] serial: uartlite: fix exit path null pointer Date: Wed, 16 Oct 2019 14:50:23 -0700 Message-Id: <20191016214811.705472460@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191016214729.758892904@linuxfoundation.org> References: <20191016214729.758892904@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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: stable Cc: Peter Korsgaard Link: https://lore.kernel.org/r/9c8e6581-6fcc-a595-0897-4d90f5d710df@infradead.org Signed-off-by: Greg Kroah-Hartman --- 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 @@ -701,7 +701,8 @@ 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);