gb_lights_light_config() stores channel_count before allocating the channels array. If kcalloc() fails, gb_lights_release() iterates the non-zero count and dereferences light->channels, which is NULL.
Allocate channels first and only then publish channels_count so the cleanup path can't walk a NULL pointer.
Fixes: 2870b52bae4c ("greybus: lights: add lights implementation") Link: https://lore.kernel.org/all/20260108103700.15384-1-chaitanyamishra.ai@gmail.... Reviewed-by: Rui Miguel Silva rui.silva@linaro.org Signed-off-by: Chaitanya Mishra chaitanyamishra.ai@gmail.com --- Changes in v4: - Add Link to v1 and carry Reviewed-by. - Tested: make defconfig, make modules_prepare, make M=drivers/staging/greybus/ modules (AWS EC2 eu-central-2, Amazon Linux 2023 x86_64).
Changes in v3: - Add version changelog below the --- line (no code changes).
drivers/staging/greybus/light.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/staging/greybus/light.c b/drivers/staging/greybus/light.c index e509fdc715db..38c233a706c4 100644 --- a/drivers/staging/greybus/light.c +++ b/drivers/staging/greybus/light.c @@ -1008,14 +1008,18 @@ static int gb_lights_light_config(struct gb_lights *glights, u8 id) if (!strlen(conf.name)) return -EINVAL;
- light->channels_count = conf.channel_count; light->name = kstrndup(conf.name, NAMES_MAX, GFP_KERNEL); if (!light->name) return -ENOMEM; - light->channels = kcalloc(light->channels_count, + light->channels = kcalloc(conf.channel_count, sizeof(struct gb_channel), GFP_KERNEL); if (!light->channels) return -ENOMEM; + /* + * Publish channels_count only after channels allocation so cleanup + * doesn't walk a NULL channels pointer on allocation failure. + */ + light->channels_count = conf.channel_count;
/* First we collect all the configurations for all channels */ for (i = 0; i < light->channels_count; i++) {