From 5ddb0869bfc1bca6cfc592c74c64a026f936638c Mon Sep 17 00:00:00 2001
From: Michal Kazior <michal@plume.com>
Date: Mon, 11 Feb 2019 10:29:27 +0100
Subject: [PATCH] leds: lp55xx: fix null deref on firmware load failure
Git-commit: 5ddb0869bfc1bca6cfc592c74c64a026f936638c
Patch-mainline: v5.1-rc1
References: bsc#1051510
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 <michal@plume.com>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
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)
--
2.16.4