diff options
| author | Jarkko Sakkinen <jarkko@kernel.org> | 2024-07-03 19:39:27 +0300 |
|---|---|---|
| committer | Jarkko Sakkinen <jarkko.sakkinen@iki.fi> | 2024-07-05 02:12:27 +0300 |
| commit | 25ee48a55fd59c72e0bd46dd9160c2d406b5a497 (patch) | |
| tree | 76bdf260edbe90e3bcaaf6a295fbc5dd96822a19 /drivers/char/tpm | |
| parent | 661e504db04c6b7278737ee3a9116738536b4ed4 (diff) | |
tpm: Address !chip->auth in tpm2_*_auth_session()
Unless tpm_chip_bootstrap() was called by the driver, !chip->auth can cause
a null derefence in tpm2_*_auth_session(). Thus, address !chip->auth in
tpm2_*_auth_session().
Cc: stable@vger.kernel.org # v6.9+
Reported-by: Stefan Berger <stefanb@linux.ibm.com>
Closes: https://lore.kernel.org/linux-integrity/20240617193408.1234365-1-stefanb@linux.ibm.com/
Fixes: 699e3efd6c64 ("tpm: Add HMAC session start and end functions")
Tested-by: Michael Ellerman <mpe@ellerman.id.au> # ppc
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Diffstat (limited to 'drivers/char/tpm')
| -rw-r--r-- | drivers/char/tpm/tpm2-sessions.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/drivers/char/tpm/tpm2-sessions.c b/drivers/char/tpm/tpm2-sessions.c index 907ac9956a78..2f1d96a5a5a7 100644 --- a/drivers/char/tpm/tpm2-sessions.c +++ b/drivers/char/tpm/tpm2-sessions.c @@ -824,8 +824,13 @@ EXPORT_SYMBOL(tpm_buf_check_hmac_response); */ void tpm2_end_auth_session(struct tpm_chip *chip) { - tpm2_flush_context(chip, chip->auth->handle); - memzero_explicit(chip->auth, sizeof(*chip->auth)); + struct tpm2_auth *auth = chip->auth; + + if (!auth) + return; + + tpm2_flush_context(chip, auth->handle); + memzero_explicit(auth, sizeof(*auth)); } EXPORT_SYMBOL(tpm2_end_auth_session); @@ -907,6 +912,11 @@ int tpm2_start_auth_session(struct tpm_chip *chip) int rc; u32 null_key; + if (!auth) { + dev_warn_once(&chip->dev, "auth session is not active\n"); + return 0; + } + rc = tpm2_load_null(chip, &null_key); if (rc) goto out; |