Hello Srinivas Pandruvada,
The patch 49a474c7ba51: "platform/x86: Add support for Uncore
frequency control" from Jan 13, 2020, leads to the following static
checker warning:
drivers/platform/x86/intel-uncore-frequency.c:285 uncore_remove_die_entry()
error: dereferencing freed memory 'data'
drivers/platform/x86/intel-uncore-frequency.c
276 /* Last CPU in this die is offline, so remove sysfs entries */
277 static void uncore_remove_die_entry(int cpu)
278 {
279 struct uncore_data *data;
280
281 mutex_lock(&uncore_lock);
282 data = uncore_get_instance(cpu);
283 if (data) {
284 kobject_put(&data->kobj);
^^^^^^^^^^^^^^^^^^^^^^^^
This leads to a slightly delayed free.
285 data->control_cpu = -1;
^^^^^^^^^^^^^^^^^
286 data->valid = false;
^^^^^^^^^^^
Why do we need to do this? It could lead to a use after free if we
got really unlucky, right?
287 }
288 mutex_unlock(&uncore_lock);
289 }
regards,
dan carpenter
