[PATCH] greybus: Fix deref of NULL in __gb_lights_flash_brightness_set

[Mikhail Lobanov]

Dereference of null pointer in the __gb_lights_flash_brightness_set function.
Assigning the channel the result of executing the get_channel_from_mode function
without checking for NULL may result in an error.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 2870b52bae4c ("greybus: lights: add lights implementation")
Signed-off-by: Mikhail Lobanov <m.lobanov@xxxxxxxxxxxx>
---
 drivers/staging/greybus/light.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/greybus/light.c b/drivers/staging/greybus/light.c
index 87d36948c610..929514350947 100644
--- a/drivers/staging/greybus/light.c
+++ b/drivers/staging/greybus/light.c
@@ -148,10 +148,15 @@ static int __gb_lights_flash_brightness_set(struct gb_channel *channel)
 						GB_CHANNEL_MODE_TORCH);
 
 	/* For not flash we need to convert brightness to intensity */
-	intensity = channel->intensity_uA.min +
+
+	if (channel) {
+		intensity = channel->intensity_uA.min +
 			(channel->intensity_uA.step * channel->led->brightness);
 
-	return __gb_lights_flash_intensity_set(channel, intensity);
+		return __gb_lights_flash_intensity_set(channel, intensity);
+	}
+
+	return 0;
 }
 #else
 static struct gb_channel *get_channel_from_cdev(struct led_classdev *cdev)
-- 
2.43.0