From: Tadeusz Struk tstruk@gmail.com
commit 2e8e4c8f6673247e22efc7985ce5497accd16f88 upstream.
When an invalid (non existing) handle is used in a TPM command, that uses the resource manager interface (/dev/tpmrm0) the resource manager tries to load it from its internal cache, but fails and the tpm_dev_transmit returns an -EINVAL error to the caller. The existing async handler doesn't handle these error cases currently and the condition in the poll handler never returns mask with EPOLLIN set. The result is that the poll call blocks and the application gets stuck until the user_read_timer wakes it up after 120 sec. Change the tpm_dev_async_work function to handle error conditions returned from tpm_dev_transmit they are also reflected in the poll mask and a correct error code could passed back to the caller.
Cc: Jarkko Sakkinen jarkko@kernel.org Cc: Jason Gunthorpe jgg@ziepe.ca Cc: linux-integrity@vger.kernel.org Cc: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org
Fixes: 9e1b74a63f77 ("tpm: add support for nonblocking operation") Tested-by: Jarkko Sakkinenjarkko@kernel.org Signed-off-by: Tadeusz Struk tstruk@gmail.com Reviewed-by: Jarkko Sakkinen jarkko@kernel.org Signed-off-by: Jarkko Sakkinen jarkko@kernel.org Cc: Tadeusz Struk tadeusz.struk@linaro.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/char/tpm/tpm-dev-common.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)
--- a/drivers/char/tpm/tpm-dev-common.c +++ b/drivers/char/tpm/tpm-dev-common.c @@ -69,7 +69,13 @@ static void tpm_dev_async_work(struct wo ret = tpm_dev_transmit(priv->chip, priv->space, priv->data_buffer, sizeof(priv->data_buffer)); tpm_put_ops(priv->chip); - if (ret > 0) { + + /* + * If ret is > 0 then tpm_dev_transmit returned the size of the + * response. If ret is < 0 then tpm_dev_transmit failed and + * returned an error code. + */ + if (ret != 0) { priv->response_length = ret; mod_timer(&priv->user_read_timer, jiffies + (120 * HZ)); }