Merge branch 'fixes-v5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security

Pull TPM fixes from James Morris:
 "From Jarkko: These are critical fixes for v5.1. Contains also couple
  of new selftests for v5.1 features (partial reads in /dev/tpm0)"

* 'fixes-v5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  selftests/tpm2: Open tpm dev in unbuffered mode
  selftests/tpm2: Extend tests to cover partial reads
  KEYS: trusted: fix -Wvarags warning
  tpm: Fix the type of the return value in calc_tpm2_event_size()
  KEYS: trusted: allow trusted.ko to initialize w/o a TPM
  tpm: fix an invalid condition in tpm_common_poll
  tpm: turn on TPM on suspend for TPM 1.x

3 files changed, 16 insertions, 11 deletions

diff --git a/drivers/char/tpm/eventlog/tpm2.c b/drivers/char/tpm/eventlog/tpm2.c
index d8b77133a83a..f824563fc28d 100644
--- a/drivers/char/tpm/eventlog/tpm2.c
+++ b/drivers/char/tpm/eventlog/tpm2.c
@@ -37,8 +37,8 @@
  *
  * Returns size of the event. If it is an invalid event, returns 0.
  */
-static int calc_tpm2_event_size(struct tcg_pcr_event2_head *event,
-				struct tcg_pcr_event *event_header)
+static size_t calc_tpm2_event_size(struct tcg_pcr_event2_head *event,
+				   struct tcg_pcr_event *event_header)
 {
 	struct tcg_efi_specid_event_head *efispecid;
 	struct tcg_event_field *event_field;
diff --git a/drivers/char/tpm/tpm-dev-common.c b/drivers/char/tpm/tpm-dev-common.c
index 8856cce5a23b..817ae09a369e 100644
--- a/drivers/char/tpm/tpm-dev-common.c
+++ b/drivers/char/tpm/tpm-dev-common.c
@@ -233,12 +233,19 @@ __poll_t tpm_common_poll(struct file *file, poll_table *wait)
 	__poll_t mask = 0;
 
 	poll_wait(file, &priv->async_wait, wait);
+	mutex_lock(&priv->buffer_mutex);
 
-	if (!priv->response_read || priv->response_length)
+	/*
+	 * The response_length indicates if there is still response
+	 * (or part of it) to be consumed. Partial reads decrease it
+	 * by the number of bytes read, and write resets it the zero.
+	 */
+	if (priv->response_length)
 		mask = EPOLLIN | EPOLLRDNORM;
 	else
 		mask = EPOLLOUT | EPOLLWRNORM;
 
+	mutex_unlock(&priv->buffer_mutex);
 	return mask;
 }
 
diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index 83ece5639f86..ae1030c9b086 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -402,15 +402,13 @@ int tpm_pm_suspend(struct device *dev)
 	if (chip->flags & TPM_CHIP_FLAG_ALWAYS_POWERED)
 		return 0;
 
-	if (chip->flags & TPM_CHIP_FLAG_TPM2) {
-		mutex_lock(&chip->tpm_mutex);
-		if (!tpm_chip_start(chip)) {
+	if (!tpm_chip_start(chip)) {
+		if (chip->flags & TPM_CHIP_FLAG_TPM2)
 			tpm2_shutdown(chip, TPM2_SU_STATE);
-			tpm_chip_stop(chip);
-		}
-		mutex_unlock(&chip->tpm_mutex);
-	} else {
-		rc = tpm1_pm_suspend(chip, tpm_suspend_pcr);
+		else
+			rc = tpm1_pm_suspend(chip, tpm_suspend_pcr);
+
+		tpm_chip_stop(chip);
 	}
 
 	return rc;