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=-9.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 91711C10F11 for ; Wed, 24 Apr 2019 17:17:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 61083218B0 for ; Wed, 24 Apr 2019 17:17:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556126252; bh=93q5ndmU19HCY2kp3tFUl2volvmrYtN71ELT/eAbtwg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=RvFrqTLQIw4d1ZQ+gQ13Q0je6iCYeGy/z7v+cYB5Ctw3K9xl5lXNwDpnYBkMpg/Yj U6pcZPGkp/g9J5AFzGUVU1IqIlzv7lHWuderYTh20SOLtfTq+T1Vw8W6AC/iMvCFuF 9FdJfrU8UrEUQrxzHABcufbYwB+2lB3Uevh+48bs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388648AbfDXRRb (ORCPT ); Wed, 24 Apr 2019 13:17:31 -0400 Received: from mail.kernel.org ([198.145.29.99]:42382 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387587AbfDXRR3 (ORCPT ); Wed, 24 Apr 2019 13:17:29 -0400 Received: from localhost (62-193-50-229.as16211.net [62.193.50.229]) (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 DFE6021917; Wed, 24 Apr 2019 17:17:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556126248; bh=93q5ndmU19HCY2kp3tFUl2volvmrYtN71ELT/eAbtwg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bMm5LmgdIMcw8oakQZtDtlFjn47iS5lavMrWxjswPYj4/9wfNr1AnHfWSL+dO17B5 8JOWF4KmlhnC6Gzu0cdX8la6ANl1kLtGrsSQpMEmdqhMekneqXv/kW5Cw+DFgC1xym 5Dhw1s6D+4QoNcnR4KNjzCRfEiiSUqnnep7Kmy40= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Michal Kazior , Jacek Anaszewski , Sasha Levin Subject: [PATCH 4.4 042/168] leds: lp55xx: fix null deref on firmware load failure Date: Wed, 24 Apr 2019 19:08:06 +0200 Message-Id: <20190424170926.281851255@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190424170923.452349382@linuxfoundation.org> References: <20190424170923.452349382@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 [ Upstream commit 5ddb0869bfc1bca6cfc592c74c64a026f936638c ] 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: Sasha Levin --- drivers/leds/leds-lp55xx-common.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/leds/leds-lp55xx-common.c b/drivers/leds/leds-lp55xx-common.c index 59b76833f0d3..fd077c176a62 100644 --- a/drivers/leds/leds-lp55xx-common.c +++ b/drivers/leds/leds-lp55xx-common.c @@ -200,7 +200,7 @@ static void lp55xx_firmware_loaded(const struct firmware *fw, void *context) if (!fw) { dev_err(dev, "firmware request failed\n"); - goto out; + return; } /* handling firmware data is chip dependent */ @@ -213,9 +213,9 @@ static void lp55xx_firmware_loaded(const struct firmware *fw, void *context) 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) -- 2.19.1