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 --- v1[1] -> v2: GregKh: - remove overkill WARN_ON and replace it for a dev_err

[1]: https://lore.kernel.org/all/20240307094838.688281-1-rmfrfs@gmail.com/

drivers/staging/greybus/light.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/staging/greybus/light.c b/drivers/staging/greybus/light.c index c6bd86a5335a..9999f8401699 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 +552,10 @@ 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 (!channel_flash) { + dev_err(dev, "failed to get flash channel from mode\n"); + return -EINVAL; + }

fled = &channel_flash->fled;