Re: [PATCH] PM: EM: Fix memory leak in em_create_pd() error path

[Changwoo Min <changwoo@igalia.com>]

Thanks, Malaya, for the bug fix. This makes sense to me.

Reviewed-by:  Changwoo Min <changwoo@igalia.com>

On 1/5/26 7:37 PM, Malaya Kumar Rout wrote:
> When ida_alloc() fails in em_create_pd(), the function returns without
> freeing the previously allocated 'pd' structure, leading to a memory leak.
> The 'pd' pointer is allocated either at line 436 (for CPU devices with
> cpumask) or line 442 (for other devices) using kzalloc().
> 
> Additionally, the function incorrectly returns -ENOMEM when ida_alloc()
> fails, ignoring the actual error code returned by ida_alloc(), which can
> fail for reasons other than memory exhaustion.
> 
> Fix both issues by:
> 1. Freeing the 'pd' structure with kfree() when ida_alloc() fails
> 2. Returning the actual error code from ida_alloc() instead of -ENOMEM
> 
> This ensures proper cleanup on the error path and accurate error reporting.
> 
> Fixes: cbe5aeedecc7 ("PM: EM: Assign a unique ID when creating a performance domain")
> Signed-off-by: Malaya Kumar Rout <mrout@redhat.com>
> ---
>   kernel/power/energy_model.c | 6 ++++--
>   1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/kernel/power/energy_model.c b/kernel/power/energy_model.c
> index 11af9f64aa82..5b055cbe5341 100644
> --- a/kernel/power/energy_model.c
> +++ b/kernel/power/energy_model.c
> @@ -449,8 +449,10 @@ static int em_create_pd(struct device *dev, int nr_states,
>   	INIT_LIST_HEAD(&pd->node);
>   
>   	id = ida_alloc(&em_pd_ida, GFP_KERNEL);
> -	if (id < 0)
> -		return -ENOMEM;
> +	if (id < 0) {
> +		kfree(pd);
> +		return id;
> +	}
>   	pd->id = id;
>   
>   	em_table = em_table_alloc(pd);