diff options
| author | James Bottomley | 2022-03-07 15:58:03 -0500 |
|---|---|---|
| committer | Jarkko Sakkinen | 2022-03-10 01:47:25 +0200 |
| commit | fb5abce6b2bb5cb3d628aaa63fa821da8c4600f9 (patch) | |
| tree | 9b793c970faa62f8e13e9474b35dd0c189ffffb3 /drivers/char | |
| parent | 590bfb57b2328951d5833979e7ca1d5fde2e609a (diff) | |
tpm: use try_get_ops() in tpm-space.c
As part of the series conversion to remove nested TPM operations:
https://lore.kernel.org/all/20190205224723.19671-1-jarkko.sakkinen@linux.intel.com/
exposure of the chip->tpm_mutex was removed from much of the upper
level code. In this conversion, tpm2_del_space() was missed. This
didn't matter much because it's usually called closely after a
converted operation, so there's only a very tiny race window where the
chip can be removed before the space flushing is done which causes a
NULL deref on the mutex. However, there are reports of this window
being hit in practice, so fix this by converting tpm2_del_space() to
use tpm_try_get_ops(), which performs all the teardown checks before
acquring the mutex.
Cc: stable@vger.kernel.org # 5.4.x
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Diffstat (limited to 'drivers/char')
| -rw-r--r-- | drivers/char/tpm/tpm2-space.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/char/tpm/tpm2-space.c b/drivers/char/tpm/tpm2-space.c index 265ec72b1d81..ffb35f0154c1 100644 --- a/drivers/char/tpm/tpm2-space.c +++ b/drivers/char/tpm/tpm2-space.c @@ -58,12 +58,12 @@ int tpm2_init_space(struct tpm_space *space, unsigned int buf_size) void tpm2_del_space(struct tpm_chip *chip, struct tpm_space *space) { - mutex_lock(&chip->tpm_mutex); - if (!tpm_chip_start(chip)) { + + if (tpm_try_get_ops(chip) == 0) { tpm2_flush_sessions(chip, space); - tpm_chip_stop(chip); + tpm_put_ops(chip); } - mutex_unlock(&chip->tpm_mutex); + kfree(space->context_buf); kfree(space->session_buf); } |