Re: [PATCH v2 0/4] Fix some errors in the devfreq core layer when governor is NULL

[Jie Zhan]

On 4/1/2026 11:28 AM, Yaxiong Tian wrote:
> While doing some development work with devfreq_add_governor()/
> devfreq_remove_governor(), I discovered several bugs caused when
> devfreq->governor is NULL. Specifically:
> 
> 1) A possible null pointer issue in devfreq_add_governor(), caused
> by devfreq_remove_governor() setting devfreq->governor to NULL in
> certain situations, while devfreq_add_governor() lacks corresponding
> checks for devfreq->governor.
> 
> 2) When operating on governor and available_governors under /sys,
> there are also some unexpected errors.
> 
> For issue 1, the solution is similar to Jie Zhan's PATCH.
> https://lore.kernel.org/linux-pm/20260326123428.800407-6-zhanjie9@xxxxxxxxxxxxx/
> 
> The original v1 approach actually changed the original logic, which is incorrect.
> 
> See the following patches for details.
> 
> change in v2:
> 1) rebase to  linux-next(20260326) /devfreq-next 
> 2) remove some code to fix null pointer in patch1
> 3) add  sysfs_update_group() in patch2
> 
> 
> Yaxiong Tian (4):
>   PM / devfreq: Fix possible null pointer issue in
>     devfreq_add_governor()
>   PM / devfreq: Fix available_governors_show() when no governor is set
>   PM / devfreq: Fix governor_store() failing when device has no current
>     governor
>   PM / devfreq: Optimize error return value of governor_show()
> 
>  drivers/devfreq/devfreq.c | 57 +++++++++++----------------------------
>  1 file changed, 16 insertions(+), 41 deletions(-)
> 

Hi Yaxiong,

Any plan for updating this in the 7.1 cycle?

Jie