From 2e8e4c8f6673247e22efc7985ce5497accd16f88 Mon Sep 17 00:00:00 2001 From: Tadeusz Struk Date: Sat, 15 Jan 2022 17:26:26 -0800 Subject: [PATCH] tpm: Fix error handling in async work 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 Cc: Jason Gunthorpe Cc: Cc: Cc: Fixes: 9e1b74a63f77 ("tpm: add support for nonblocking operation") Tested-by: Jarkko Sakkinen Signed-off-by: Tadeusz Struk Reviewed-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen --- drivers/char/tpm/tpm-dev-common.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/char/tpm/tpm-dev-common.c b/drivers/char/tpm/tpm-dev-common.c index c08cbb306636..dc4c0a0a5129 100644 --- 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 work_struct *work) 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)); }