From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sasha Levin Subject: [PATCH AUTOSEL 5.0 138/262] leds: lp55xx: fix null deref on firmware load failure Date: Wed, 27 Mar 2019 13:59:53 -0400 Message-ID: <20190327180158.10245-138-sashal@kernel.org> References: <20190327180158.10245-1-sashal@kernel.org> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20190327180158.10245-1-sashal@kernel.org> Sender: linux-kernel-owner@vger.kernel.org To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Michal Kazior , Jacek Anaszewski , Sasha Levin , linux-leds@vger.kernel.org List-Id: linux-leds@vger.kernel.org From: Michal Kazior [ 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 3d79a6380761..723f2f17497a 100644 --- a/drivers/leds/leds-lp55xx-common.c +++ b/drivers/leds/leds-lp55xx-common.c @@ -201,7 +201,7 @@ 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 */ @@ -214,9 +214,9 @@ 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