Re: [PATCH] leds: fix a missing check of return value of lp55xx_read

[Jacek Anaszewski]

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 
---
  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, );
+   ret = lp55xx_read(chip, LP5523_REG_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

[PATCH] leds: fix a missing check of return value of lp55xx_read

[Kangjie Lu]

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 
---
 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, );
+   ret = lp55xx_read(chip, LP5523_REG_STATUS, );
+   if (ret)
+   return ret;
status &= LP5523_ENG_STATUS_MASK;
 
if (status != LP5523_ENG_STATUS_MASK) {
-- 
2.17.2 (Apple Git-113)