Re: [PATCH v2 1/3] tpm: acpi: Call acpi_put_table() to fix memory leak

[Jarkko Sakkinen]

On Thu, Nov 17, 2022 at 07:23:40PM +0800, Hanjun Guo wrote:
> The start and length of the event log area are obtained from
> TPM2 or TCPA table, so we call acpi_get_table() to get the
> ACPI information, but the acpi_get_table() should be coupled with
> acpi_put_table() to release the ACPI memory, add the acpi_put_table()
> properly to fix the memory leak.
> 
> While we are at it, remove the redundant empty line at the
> end of the tpm_read_log_acpi().
> 
> Fixes: 0bfb23746052 ("tpm: Move eventlog files to a subdirectory")
> Fixes: 85467f63a05c ("tpm: Add support for event log pointer found in TPM2 ACPI table")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Hanjun Guo <guohanjun@xxxxxxxxxx>
> ---
>  drivers/char/tpm/eventlog/acpi.c | 12 +++++++++---
>  1 file changed, 9 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/char/tpm/eventlog/acpi.c b/drivers/char/tpm/eventlog/acpi.c
> index 1b18ce5..0913d3eb 100644
> --- a/drivers/char/tpm/eventlog/acpi.c
> +++ b/drivers/char/tpm/eventlog/acpi.c
> @@ -90,16 +90,21 @@ int tpm_read_log_acpi(struct tpm_chip *chip)
>  			return -ENODEV;
>  
>  		if (tbl->header.length <
> -				sizeof(*tbl) + sizeof(struct acpi_tpm2_phy))
> +				sizeof(*tbl) + sizeof(struct acpi_tpm2_phy)) {
> +			acpi_put_table((struct acpi_table_header *)tbl);
>  			return -ENODEV;
> +		}
>  
>  		tpm2_phy = (void *)tbl + sizeof(*tbl);
>  		len = tpm2_phy->log_area_minimum_length;
>  
>  		start = tpm2_phy->log_area_start_address;
> -		if (!start || !len)
> +		if (!start || !len) {
> +			acpi_put_table((struct acpi_table_header *)tbl);
>  			return -ENODEV;
> +		}
>  
> +		acpi_put_table((struct acpi_table_header *)tbl);
>  		format = EFI_TCG2_EVENT_LOG_FORMAT_TCG_2;
>  	} else {
>  		/* Find TCPA entry in RSDT (ACPI_LOGICAL_ADDRESSING) */
> @@ -120,8 +125,10 @@ int tpm_read_log_acpi(struct tpm_chip *chip)
>  			break;
>  		}
>  
> +		acpi_put_table((struct acpi_table_header *)buff);
>  		format = EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2;
>  	}
> +
>  	if (!len) {
>  		dev_warn(&chip->dev, "%s: TCPA log area empty\n", __func__);
>  		return -EIO;
> @@ -156,5 +163,4 @@ int tpm_read_log_acpi(struct tpm_chip *chip)
>  	kfree(log->bios_event_log);
>  	log->bios_event_log = NULL;
>  	return ret;
> -
>  }
> -- 
> 1.7.12.4
> 

Reviewed-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx>

BR, Jarkko