[PATCH] greybus: lights: check return of get_channel_from_mode

Rui Miguel Silva
2024-03-07T09:49:05Z

If channel for the given node is not found we return null from
get_channel_from_mode. Make sure we validate the return pointer
before using it in two of the missing places.

This was originally reported in [0]:
Found by Linux Verification Center (linuxtesting.org) with SVACE.

[0] https://lore.kernel.org/all/20240301190425.120605-1-m.lobanov@rosalinux.ru

Fixes: 2870b52bae4c ("greybus: lights: add lights implementation")
Reported-by: Mikhail Lobanov <m.lobanov@rosalinux.ru>
Suggested-by: Mikhail Lobanov <m.lobanov@rosalinux.ru>
Suggested-by: Alex Elder <elder@ieee.org>
Signed-off-by: Rui Miguel Silva <rmfrfs@gmail.com>
---
drivers/staging/greybus/light.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/staging/greybus/light.c b/drivers/staging/greybus/light.c
index c6bd86a5335a..6f10b9e2c053 100644
--- a/drivers/staging/greybus/light.c
+++ b/drivers/staging/greybus/light.c
@@ -147,6 +147,9 @@ static int __gb_lights_flash_brightness_set(struct gb_channel *channel)
channel = get_channel_from_mode(channel->light,
GB_CHANNEL_MODE_TORCH);

+ if (!channel)
+ return -EINVAL;
+
/* For not flash we need to convert brightness to intensity */
intensity = channel->intensity_uA.min +
(channel->intensity_uA.step * channel->led->brightness);
@@ -549,7 +552,8 @@ static int gb_lights_light_v4l2_register(struct gb_light *light)
}

channel_flash = get_channel_from_mode(light, GB_CHANNEL_MODE_FLASH);
- WARN_ON(!channel_flash);
+ if (WARN_ON(!channel_flash))
+ return -EINVAL;

fled = &channel_flash->fled;

--
2.44.0