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

From: Jarkko Sakkinen
Date: Sun Nov 27 2022 - 12:19:06 EST


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