KEYS: trusted: Fix TPM reservation for seal/unseal

The original patch 8c657a0590de ("KEYS: trusted: Reserve TPM for seal
and unseal operations") was correct on the mailing list:

https://lore.kernel.org/linux-integrity/20210128235621.127925-4-jarkko@kernel.org/

But somehow got rebased so that the tpm_try_get_ops() in
tpm2_seal_trusted() got lost.  This causes an imbalanced put of the
TPM ops and causes oopses on TIS based hardware.

This fix puts back the lost tpm_try_get_ops()

Fixes: 8c657a0590de ("KEYS: trusted: Reserve TPM for seal and unseal operations")
Reported-by: Mimi Zohar <zohar@linux.ibm.com>
Acked-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c
index e2a0ed5d02f013392d337a1b543eeda1e986ba74..c87c4df8703d4ea9426cebab43846ed69fb04ddd 100644 (file)
--- a/security/keys/trusted-keys/trusted_tpm2.c
+++ b/security/keys/trusted-keys/trusted_tpm2.c
@@ -79,7 +79,7 @@ int tpm2_seal_trusted(struct tpm_chip *chip,
        if (i == ARRAY_SIZE(tpm2_hash_map))
                return -EINVAL;
 
-       rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_CREATE);
+       rc = tpm_try_get_ops(chip);
        if (rc)
                return rc;