Re: [PATCH v2 0/9] thermal/core: Protect thermal device operations against removal

[Rafael J. Wysocki]

On Thu, Nov 10, 2022 at 4:25 PM Guenter Roeck <linux@xxxxxxxxxxxx> wrote:
>
> Accesses to thermal zones, and with it to thermal zone device operations,
> are still possible after the thermal zone device has been unregistered.
> For example, thermal_zone_get_temp() can be called from temp_show()
> in thermal_sysfs.c if the sysfs attribute was opened before the thermal
> device was unregistered. This is problematic and may result in crashes
> since the operations data structure and the underlying code may be gone
> when the calls are made.
>
> The following series solves the problem by protecting accesses to thermal
> device operations with the thermal device mutex, and by verifying that the
> thermal device is still registered after the mutex has been acquired.
>
> This was previously sent as RFC/RFT as single patch [1]. The code was reworked
> to match thermal subsystem changes made between v6.0 and v6.1, and it was
> split into several patches to simplify review.
>
> [1] https://lore.kernel.org/linux-pm/20221004033936.1047691-1-linux@xxxxxxxxxxxx/
>
> v2: Improved documentation, rearranged code.
>     No functional changes. See individual patches for details.
>
> ----------------------------------------------------------------
> Guenter Roeck (9):
>       thermal/core: Destroy thermal zone device mutex in release function
>       thermal/core: Delete device under thermal device zone lock
>       thermal/core: Ensure that thermal device is registered in thermal_zone_get_temp
>       thermal/core: Move parameter validation from __thermal_zone_get_temp to thermal_zone_get_temp
>       thermal/core: Introduce locked version of thermal_zone_device_update
>       thermal/core: Protect hwmon accesses to thermal operations with thermal zone mutex
>       thermal/core: Protect sysfs accesses to thermal operations with thermal zone mutex
>       thermal/core: Remove thermal_zone_set_trips()
>       thermal/core: Protect thermal device operations against thermal device removal
>
>  drivers/thermal/thermal_core.c    | 76 +++++++++++++++++++++++--------------
>  drivers/thermal/thermal_core.h    |  3 +-
>  drivers/thermal/thermal_helpers.c | 67 +++++++++++++++++++++------------
>  drivers/thermal/thermal_hwmon.c   | 10 ++++-
>  drivers/thermal/thermal_sysfs.c   | 79 ++++++++++++++++++++++++++++++++-------
>  5 files changed, 168 insertions(+), 67 deletions(-)

All applied as 6.2 material, thanks!