HID: intel-ish-hid: Fix use-after-free issue in ishtp_hid_remove()

The system can experience a random crash a few minutes after the driver is
removed. This issue occurs due to improper handling of memory freeing in
the ishtp_hid_remove() function.

The function currently frees the `driver_data` directly within the loop
that destroys the HID devices, which can lead to accessing freed memory.
Specifically, `hid_destroy_device()` uses `driver_data` when it calls
`hid_ishtp_set_feature()` to power off the sensor, so freeing
`driver_data` beforehand can result in accessing invalid memory.

This patch resolves the issue by storing the `driver_data` in a temporary
variable before calling `hid_destroy_device()`, and then freeing the
`driver_data` after the device is destroyed.

Fixes: 0b28cb4bcb17 ("HID: intel-ish-hid: ISH HID client driver")
Signed-off-by: Zhang Lixu <lixu.zhang@intel.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>

diff --git a/drivers/hid/intel-ish-hid/ishtp-hid.c b/drivers/hid/intel-ish-hid/ishtp-hid.c
index 00c6f0ebf356335efb18dcdb31b912bb820c1561..be2c62fc8251d7bf591e3b87ff0dc189f065e1b5 100644 (file)
--- a/drivers/hid/intel-ish-hid/ishtp-hid.c
+++ b/drivers/hid/intel-ish-hid/ishtp-hid.c
@@ -261,12 +261,14 @@ err_hid_data:
  */
 void ishtp_hid_remove(struct ishtp_cl_data *client_data)
 {
+       void *data;
        int i;
 
        for (i = 0; i < client_data->num_hid_devices; ++i) {
                if (client_data->hid_sensor_hubs[i]) {
-                       kfree(client_data->hid_sensor_hubs[i]->driver_data);
+                       data = client_data->hid_sensor_hubs[i]->driver_data;
                        hid_destroy_device(client_data->hid_sensor_hubs[i]);
+                       kfree(data);
                        client_data->hid_sensor_hubs[i] = NULL;
                }
        }