Re: [PATCH] tpm: fix a race condition in tpm2_unseal_trusted()
From: Jason Gunthorpe <hidden>
Date: 2016-08-28 18:52:10
Also in:
lkml
On Sun, Aug 28, 2016 at 08:36:52AM +0200, Jarkko Sakkinen wrote:
quoted hunk ↗ jump to hunk
@@ -576,7 +576,8 @@ static int tpm2_load(struct tpm_chip *chip, goto out; } - rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, "loading blob"); + rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, TPM_TRANSMIT_UNLOCKED, + "loading blob");
I still don't like this, required mutex's should not be split outside the function that needs them without more a more obvious indication:
+ mutex_lock(&chip->tpm_mutex); rc = tpm2_load(chip, payload, options, &blob_handle); if (rc) - return rc;
I recommend you stick with the idiom and do this:
mutex_lock(&chip->tpm_mutex);
rc = tpm2_load(chip, payload, options, &blob_handle, TPM_TRANSMIT_UNLOCKED);
Which makes it easy to see we are doing it right everywhere.
Jason