Commit c78719203fc6 ("KEYS: trusted: allow trusted.ko to initialize w/o a
TPM") allows the trusted module to be loaded even a TPM is not found to
avoid module dependency problems.
However, trusted module initialization can still fail if the TPM is
inactive or deactivated. This patch ignores tpm_get_random() errors in
init_digests() and returns -EFAULT in pcrlock() if the TPM didn't return
random data.
Signed-off-by: Roberto Sassu <roberto.sassu@xxxxxxxxxx>
---
security/keys/trusted.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/security/keys/trusted.c b/security/keys/trusted.c
index 9a94672e7adc..34f04ffcf2e5 100644
--- a/security/keys/trusted.c
+++ b/security/keys/trusted.c
@@ -389,6 +389,10 @@ static int pcrlock(const int pcrnum)
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
+ /* This happens if the TPM didn't return random data */
+ if (!digests)
+ return -EFAULT;
+
return tpm_pcr_extend(chip, pcrnum, digests) ? -EINVAL : 0;
}
@@ -1233,10 +1237,8 @@ static int __init init_digests(void)
int i;
ret = tpm_get_random(chip, digest, TPM_MAX_DIGEST_SIZE);
- if (ret < 0)
- return ret;
- if (ret < TPM_MAX_DIGEST_SIZE)
- return -EFAULT;
+ if (ret < 0 || ret < TPM_MAX_DIGEST_SIZE)
+ return 0;
digests = kcalloc(chip->nr_allocated_banks, sizeof(*digests),
GFP_KERNEL);
--
2.17.1
