[PATCH v4] tpm2: add longer timeout for verify signature command

amirmizi6
2021-05-25T11:13:56Z

From: Amir Mizinski <amirmizi6@gmail.com>

While running a TPM2_CC_VERIFY_SIGNATURE operation with RSA 3072-bit
keys the TPM driver fails with the following error:

"kernel: [ 2416.187522] tpm tpm0: Operation Timed out"

Since the TPM PC Client specification does not specify a number for
verify signature operation timeout, and the duration of
TPM2_CC_VERIFY_SIGNATURE with RSA 3072-bit keys exceeds the current timeout
of TPM_LONG (2 seconds), it is preferable to pick the longest timeout
possible.

Therefore, set the duration for TPM2_CC_VERIFY_SIGNATUE to TPM_LONG_LONG
(5 minutes).

Link: https://trustedcomputinggroup.org/resource/pc-client-specific-platform-firmware-profile-specification/
Signed-off-by: Amir Mizinski <amirmizi6@gmail.com>
---
drivers/char/tpm/tpm2-cmd.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
index 7603295..e71154b 100644
--- a/drivers/char/tpm/tpm2-cmd.c
+++ b/drivers/char/tpm/tpm2-cmd.c
@@ -87,7 +87,7 @@ static u8 tpm2_ordinal_duration_index(u32 ordinal)
return TPM_MEDIUM;

case TPM2_CC_VERIFY_SIGNATURE: /* 177 */
- return TPM_LONG;
+ return TPM_LONG_LONG;

case TPM2_CC_PCR_EXTEND: /* 182 */
return TPM_MEDIUM;
--
2.7.4