[PATCH 5.18 1069/1095] tpm: Add check for Failure mode for TPM2 modules

From: Greg Kroah-Hartman
Date: Mon Aug 15 2022 - 19:40:37 EST


From: Mårten Lindahl <marten.lindahl@xxxxxxxx>

[ Upstream commit 863ed94c589fcd1984f4e3080f069d30508044bb ]

In commit 0aa698787aa2 ("tpm: Add Upgrade/Reduced mode support for
TPM2 modules") it was said that:

"If the TPM is in Failure mode, it will successfully respond to both
tpm2_do_selftest() and tpm2_startup() calls. Although, will fail to
answer to tpm2_get_cc_attrs_tbl(). Use this fact to conclude that TPM
is in Failure mode."

But a check was never added in the commit when calling
tpm2_get_cc_attrs_tbl() to conclude that the TPM is in Failure mode.
This commit corrects this by adding a check.

Fixes: 0aa698787aa2 ("tpm: Add Upgrade/Reduced mode support for TPM2 modules")
Cc: stable@xxxxxxxxxxxxxxx # v5.17+
Signed-off-by: Mårten Lindahl <marten.lindahl@xxxxxxxx>
Reviewed-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
Signed-off-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/char/tpm/tpm2-cmd.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
index 04a3e23a4afc..4419593d9531 100644
--- a/drivers/char/tpm/tpm2-cmd.c
+++ b/drivers/char/tpm/tpm2-cmd.c
@@ -752,6 +752,12 @@ int tpm2_auto_startup(struct tpm_chip *chip)
}

rc = tpm2_get_cc_attrs_tbl(chip);
+ if (rc == TPM2_RC_FAILURE || (rc < 0 && rc != -ENOMEM)) {
+ dev_info(&chip->dev,
+ "TPM in field failure mode, requires firmware upgrade\n");
+ chip->flags |= TPM_CHIP_FLAG_FIRMWARE_UPGRADE;
+ rc = 0;
+ }

out:
if (rc == TPM2_RC_UPGRADE) {
--
2.35.1