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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 5D36CC48BDE for ; Sun, 7 Jul 2019 19:44:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3C93020663 for ; Sun, 7 Jul 2019 19:44:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728412AbfGGToH (ORCPT ); Sun, 7 Jul 2019 15:44:07 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:57360 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726105AbfGGTiJ (ORCPT ); Sun, 7 Jul 2019 15:38:09 -0400 Received: from 94.197.121.43.threembb.co.uk ([94.197.121.43] helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1hkCz6-0006hq-PF; Sun, 07 Jul 2019 20:38:04 +0100 Received: from ben by deadeye with local (Exim 4.92) (envelope-from ) id 1hkCz4-0005br-W5; Sun, 07 Jul 2019 20:38:02 +0100 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 , "Jacek Anaszewski" , "Michal Kazior" Date: Sun, 07 Jul 2019 17:54:17 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 069/129] leds: lp55xx: fix null deref on firmware load failure In-Reply-To: X-SA-Exim-Connect-IP: 94.197.121.43 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 3.16.70-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Michal Kazior commit 5ddb0869bfc1bca6cfc592c74c64a026f936638c upstream. I've stumbled upon a kernel crash and the logs pointed me towards the lp5562 driver: > <4>[306013.841294] lp5562 0-0030: Direct firmware load for lp5562 failed with error -2 > <4>[306013.894990] lp5562 0-0030: Falling back to user helper > ... > <3>[306073.924886] lp5562 0-0030: firmware request failed > <1>[306073.939456] Unable to handle kernel NULL pointer dereference at virtual address 00000000 > <4>[306074.251011] PC is at _raw_spin_lock+0x1c/0x58 > <4>[306074.255539] LR is at release_firmware+0x6c/0x138 > ... After taking a look I noticed firmware_release() could be called with either NULL or a dangling pointer. Fixes: 10c06d178df11 ("leds-lp55xx: support firmware interface") Signed-off-by: Michal Kazior Signed-off-by: Jacek Anaszewski Signed-off-by: Ben Hutchings --- drivers/leds/leds-lp55xx-common.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/leds/leds-lp55xx-common.c +++ b/drivers/leds/leds-lp55xx-common.c @@ -214,7 +214,7 @@ static void lp55xx_firmware_loaded(const if (!fw) { dev_err(dev, "firmware request failed\n"); - goto out; + return; } /* handling firmware data is chip dependent */ @@ -227,9 +227,9 @@ static void lp55xx_firmware_loaded(const mutex_unlock(&chip->lock); -out: /* firmware should be released for other channel use */ release_firmware(chip->fw); + chip->fw = NULL; } static int lp55xx_request_firmware(struct lp55xx_chip *chip)