staging: bcm2835-camera: add check to avoid null pointer dereference

This patch adds checks after memory allocation to avoid possible null
pointer dereferences.
Signed-off-by: Aishwarya Pant <aishpant@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/vc04_services/bcm2835-camera/mmal-vchiq.c

@@ -260,8 +260,11 @@ get_msg_context(struct vchiq_mmal_instance *instance)
 
 	/* todo: should this be allocated from a pool to avoid kmalloc */
 	msg_context = kmalloc(sizeof(*msg_context), GFP_KERNEL);
-	memset(msg_context, 0, sizeof(*msg_context));
 
+	if (!msg_context)
+		return NULL;
+
+	memset(msg_context, 0, sizeof(*msg_context));
 	msg_context->instance = instance;
 	msg_context->handle =
 		mmal_context_map_create_handle(&instance->context_map,
@@ -2015,8 +2018,11 @@ int vchiq_mmal_init(struct vchiq_mmal_instance **out_instance)
 	}
 
 	instance = kmalloc(sizeof(*instance), GFP_KERNEL);
-	memset(instance, 0, sizeof(*instance));
 
+	if (!instance)
+		return -ENOMEM;
+
+	memset(instance, 0, sizeof(*instance));
 	mutex_init(&instance->vchiq_mutex);
 	mutex_init(&instance->bulk_mutex);