* [PATCH AUTOSEL 4.19 098/192] leds: lp55xx: fix null deref on firmware load failure
[not found] <20190327181025.13507-1-sashal@kernel.org>
@ 2019-03-27 18:08 ` Sasha Levin
0 siblings, 0 replies; only message in thread
From: Sasha Levin @ 2019-03-27 18:08 UTC (permalink / raw)
To: linux-kernel, stable
Cc: Michal Kazior, Jacek Anaszewski, Sasha Levin, linux-leds
From: Michal Kazior <michal@plume.com>
[ 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 <michal@plume.com>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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
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