Re: [PATCH v7 1/5] tpm: Return on tpm2_create_null_primary() failure

On 10/21/24 1:39 AM, Jarkko Sakkinen wrote:

tpm2_sessions_init() does not ignore the result of tpm2_create_null_primary(). Address this by returning -ENODEV to the caller. Given that upper layers cannot help healing the situation

It looks like returning -ENODEV applied to a previous version of the patch.

further, deal with the TPM error here by

This sounds like an incomplete sentence...

Cc: stable@vger.kernel.org # v6.10+ Fixes: d2add27cf2b8 ("tpm: Add NULL primary creation") Signed-off-by: Jarkko Sakkinen jarkko@kernel.org

---

v7:

• Add the error message back but fix it up a bit:
  1. Remove 'TPM:' given dev_err().
  2. s/NULL/null/ as this has nothing to do with the macro in libc.
  3. Fix the reasoning: null key creation failed

v6:

• Address: https://lore.kernel.org/linux-integrity/69c893e7-6b87-4daa-80db-44d1120e80fe... as TPM RC is taken care of at the call site. Add also the missing documentation for the return values.

v5:

• Do not print klog messages on error, as tpm2_save_context() already takes care of this.

v4:

• Fixed up stable version.

v3:

• Handle TPM and POSIX error separately and return -ENODEV always back to the caller.

v2:

• Refined the commit message.

---

drivers/char/tpm/tpm2-sessions.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/char/tpm/tpm2-sessions.c b/drivers/char/tpm/tpm2-sessions.c index d3521aadd43e..1e12e0b2492e 100644 --- a/drivers/char/tpm/tpm2-sessions.c +++ b/drivers/char/tpm/tpm2-sessions.c @@ -1347,14 +1347,21 @@ static int tpm2_create_null_primary(struct tpm_chip *chip)

• Derive and context save the null primary and allocate memory in the
• struct tpm_chip for the authorizations.

• • Return:
• • • 0 - OK
• • • -errno - A system error
• • • TPM_RC - A TPM error
  */ int tpm2_sessions_init(struct tpm_chip *chip) { int rc;

rc = tpm2_create_null_primary(chip);

• if (rc)

• dev_err(&chip->dev, "TPM: security failed (NULL seed derivation): %d\n", rc);
  

• if (rc) {

• dev_err(&chip->dev, "null primary key creation failed with %d\n", rc);
  

• return rc;
  

• }

chip->auth = kmalloc(sizeof(*chip->auth), GFP_KERNEL); if (!chip->auth)