firmware: arm_scmi: Avoid double free in error flow

If device_register() fails, both put_device() and kfree() are called,
ending with a double free of the scmi_dev.

Calling kfree() is needed only when a failure happens between the
allocation of the scmi_dev and its registration, so move it to there
and remove it from the error flow.

Fixes: 46edb8d1322c ("firmware: arm_scmi: provide the mandatory device release callback")
Signed-off-by: Wen Yang <wenyang@linux.alibaba.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

diff --git a/drivers/firmware/arm_scmi/bus.c b/drivers/firmware/arm_scmi/bus.c
index 92f843eaf1e0156cf56d7839cec8d766bff6e86f..7a30952b463d58329edd05980409b40b6b856c74 100644 (file)
--- a/drivers/firmware/arm_scmi/bus.c
+++ b/drivers/firmware/arm_scmi/bus.c
@@ -135,8 +135,10 @@ scmi_device_create(struct device_node *np, struct device *parent, int protocol)
                return NULL;
 
        id = ida_simple_get(&scmi_bus_id, 1, 0, GFP_KERNEL);
-       if (id < 0)
-               goto free_mem;
+       if (id < 0) {
+               kfree(scmi_dev);
+               return NULL;
+       }
 
        scmi_dev->id = id;
        scmi_dev->protocol_id = protocol;
@@ -154,8 +156,6 @@ scmi_device_create(struct device_node *np, struct device *parent, int protocol)
 put_dev:
        put_device(&scmi_dev->dev);
        ida_simple_remove(&scmi_bus_id, id);
-free_mem:
-       kfree(scmi_dev);
        return NULL;
 }