* [PATCH] leds: fix a missing check of return value of lp55xx_read
@ 2018-12-26 4:18 Kangjie Lu
2018-12-28 16:52 ` Jacek Anaszewski
0 siblings, 1 reply; 2+ messages in thread
From: Kangjie Lu @ 2018-12-26 4:18 UTC (permalink / raw)
To: kjlu; +Cc: pakki001, Jacek Anaszewski, Pavel Machek, linux-leds,
linux-kernel
When lp55xx_read() fails, "status" is an uninitialized variable and thus
may contain random value; using it leads to undefined behaviors.
The fix inserts a check for the return value of lp55xx_read: if it
fails, returns with its error code.
Signed-off-by: Kangjie Lu <kjlu@umn.edu>
---
drivers/leds/leds-lp5523.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/leds/leds-lp5523.c b/drivers/leds/leds-lp5523.c
index a2e74feee2b2..fd64df5a57a5 100644
--- a/drivers/leds/leds-lp5523.c
+++ b/drivers/leds/leds-lp5523.c
@@ -318,7 +318,9 @@ static int lp5523_init_program_engine(struct lp55xx_chip *chip)
/* Let the programs run for couple of ms and check the engine status */
usleep_range(3000, 6000);
- lp55xx_read(chip, LP5523_REG_STATUS, &status);
+ ret = lp55xx_read(chip, LP5523_REG_STATUS, &status);
+ if (ret)
+ return ret;
status &= LP5523_ENG_STATUS_MASK;
if (status != LP5523_ENG_STATUS_MASK) {
--
2.17.2 (Apple Git-113)
^ permalink raw reply related [flat|nested] 2+ messages in thread* Re: [PATCH] leds: fix a missing check of return value of lp55xx_read
2018-12-26 4:18 [PATCH] leds: fix a missing check of return value of lp55xx_read Kangjie Lu
@ 2018-12-28 16:52 ` Jacek Anaszewski
0 siblings, 0 replies; 2+ messages in thread
From: Jacek Anaszewski @ 2018-12-28 16:52 UTC (permalink / raw)
To: Kangjie Lu; +Cc: pakki001, Pavel Machek, linux-leds, linux-kernel
Hi Kangjie,
Thank you for the patch.
On 12/26/18 5:18 AM, Kangjie Lu wrote:
> When lp55xx_read() fails, "status" is an uninitialized variable and thus
> may contain random value; using it leads to undefined behaviors.
>
> The fix inserts a check for the return value of lp55xx_read: if it
> fails, returns with its error code.
>
> Signed-off-by: Kangjie Lu <kjlu@umn.edu>
> ---
> drivers/leds/leds-lp5523.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/leds/leds-lp5523.c b/drivers/leds/leds-lp5523.c
> index a2e74feee2b2..fd64df5a57a5 100644
> --- a/drivers/leds/leds-lp5523.c
> +++ b/drivers/leds/leds-lp5523.c
> @@ -318,7 +318,9 @@ static int lp5523_init_program_engine(struct lp55xx_chip *chip)
>
> /* Let the programs run for couple of ms and check the engine status */
> usleep_range(3000, 6000);
> - lp55xx_read(chip, LP5523_REG_STATUS, &status);
> + ret = lp55xx_read(chip, LP5523_REG_STATUS, &status);
> + if (ret)
> + return ret;
> status &= LP5523_ENG_STATUS_MASK;
>
> if (status != LP5523_ENG_STATUS_MASK) {
>
Applied to fixes-for-4.21 branch of linux-leds.git.
--
Best regards,
Jacek Anaszewski
^ permalink raw reply [flat|nested] 2+ messages in thread
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