Re: [PATCH] ACPI: PCC: Fix memory leak in address space setup

[Rafael Mendonca <rafaelmendsr@gmail.com>]

On Thu, Sep 08, 2022 at 11:13:47PM -0300, Rafael Mendonca wrote:
> The allocated memory for the pcc_data struct doesn't get freed under an
> error path in pcc_mbox_request_channel() or acpi_os_ioremap().
> 
> Fixes: 77e2a04745ff8 ("ACPI: PCC: Implement OperationRegion handler for the PCC Type 3 subtype")
> Signed-off-by: Rafael Mendonca <rafaelmendsr@gmail.com>
> ---
>  drivers/acpi/acpi_pcc.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/acpi/acpi_pcc.c b/drivers/acpi/acpi_pcc.c
> index a12b55d81209..fe5ab0fdc3bf 100644
> --- a/drivers/acpi/acpi_pcc.c
> +++ b/drivers/acpi/acpi_pcc.c
> @@ -63,6 +63,7 @@ acpi_pcc_address_space_setup(acpi_handle region_handle, u32 function,
>  	if (IS_ERR(data->pcc_chan)) {
>  		pr_err("Failed to find PCC channel for subspace %d\n",
>  		       ctx->subspace_id);
> +		kfree(data);
>  		return AE_NOT_FOUND;
>  	}
>  
> @@ -72,6 +73,7 @@ acpi_pcc_address_space_setup(acpi_handle region_handle, u32 function,
>  	if (!data->pcc_comm_addr) {
>  		pr_err("Failed to ioremap PCC comm region mem for %d\n",
>  		       ctx->subspace_id);

I was wondering if pcc_mbox_free_channel() should be called here as well
in case of acpi_os_ioremap() failure.

> +		kfree(data);
>  		return AE_NO_MEMORY;
>  	}
>  
> -- 
> 2.34.1
>