2015-06-24 14:15:10

by Jarkko Sakkinen

Subject: [PATCH] tpm, tpm_crb: fail when TPM2 ACPI table contents look corrupted

At least some versions of AMI BIOS have corrupted contents in the TPM2
ACPI table and namely the physical address of the control area is set to
zero.

This patch changes the driver to fail gracefully when we observe a zero
address instead of continuing to ioremap.

Signed-off-by: Jarkko Sakkinen <[email protected]>
---
drivers/char/tpm/tpm_crb.c | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
index b26ceee..c8fae5b 100644
--- a/drivers/char/tpm/tpm_crb.c
+++ b/drivers/char/tpm/tpm_crb.c
@@ -233,6 +233,14 @@ static int crb_acpi_add(struct acpi_device *device)
return -ENODEV;
}

+ /* At least some versions of AMI BIOS have a bug that TPM2 table has
+ * zero address for the control area and therefore we must fail.
+ */
+ if (!buf->control_area_pa) {
+ dev_err(dev, "TPM2 ACPI table has a zero address for the control area\n");
+ return -EINVAL;
+ }
+
if (buf->hdr.length < sizeof(struct acpi_tpm2)) {
dev_err(dev, "TPM2 ACPI table has wrong size");
return -EINVAL;
--
2.1.4

2015-07-13 21:09:43

by Peter Huewe

Subject: Re: [PATCH] tpm, tpm_crb: fail when TPM2 ACPI table contents look corrupted

Am Mittwoch, 24. Juni 2015, 16:14:55 schrieb Jarkko Sakkinen:
> At least some versions of AMI BIOS have corrupted contents in the TPM2
> ACPI table and namely the physical address of the control area is set to
> zero.
>
> This patch changes the driver to fail gracefully when we observe a zero
> address instead of continuing to ioremap.

Reviewed-by: Peter Huewe <[email protected]>

Thanks for fixing this.
Peter