From: Lino Sanfilippo <LinoSanfilippo@gmx.de>
To: peterhuewe@gmx.de, jarkko@kernel.org
Cc: jgg@ziepe.ca, stefanb@linux.vnet.ibm.com,
linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org,
LinoSanfilippo@gmx.de, p.rosenberger@kunbus.com,
Lino Sanfilippo <l.sanfilippo@kunbus.com>
Subject: [PATCH 3/4] tpm: in tpm2_del_space check if ops pointer is still valid
Date: Sat, 16 Jan 2021 02:22:40 +0100 [thread overview]
Message-ID: <1610760161-21982-4-git-send-email-LinoSanfilippo@gmx.de> (raw)
In-Reply-To: <1610760161-21982-1-git-send-email-LinoSanfilippo@gmx.de>
From: Lino Sanfilippo <l.sanfilippo@kunbus.com>
In tpm2_del_space() the sessions are flushed by means of the tpm_chip
operations. However the concerning operations pointer my already be NULL at
this time in case that the chip has been unregistered (see
tpm_chip_unregister() which calls tpm_del_char_device() which sets
chip->ops to NULL).
Avoid the NULL pointer access by first calling tpm_try_get_ops() to check
if the operations pointer is still valid and skipping the session flushing
in case of an unregistered chip.
Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com>
---
drivers/char/tpm/tpm2-space.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/char/tpm/tpm2-space.c b/drivers/char/tpm/tpm2-space.c
index 784b8b3..ea6eee9 100644
--- a/drivers/char/tpm/tpm2-space.c
+++ b/drivers/char/tpm/tpm2-space.c
@@ -59,7 +59,7 @@ 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) && !tpm_chip_start(chip)) {
tpm2_flush_sessions(chip, space);
tpm_chip_stop(chip);
}
--
2.7.4
next prev parent reply other threads:[~2021-01-16 1:25 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-16 1:22 [PATCH 0/4] TPM fixes Lino Sanfilippo
2021-01-16 1:22 ` [PATCH 1/4] tpm: in case of error properly cleanup in tpmm_chip_alloc Lino Sanfilippo
2021-01-17 18:08 ` Jarkko Sakkinen
2021-01-16 1:22 ` [PATCH 2/4] tpm: fix reference counting for struct tpm_chip Lino Sanfilippo
2021-01-17 18:11 ` Jarkko Sakkinen
2021-01-16 1:22 ` Lino Sanfilippo [this message]
2021-01-17 18:13 ` [PATCH 3/4] tpm: in tpm2_del_space check if ops pointer is still valid Jarkko Sakkinen
2021-01-24 16:47 ` Lino Sanfilippo
2021-01-26 15:29 ` Jarkko Sakkinen
2021-01-27 15:14 ` Lino Sanfilippo
2021-01-16 1:22 ` [PATCH 4/4] tpm: Provide a function tpm_chip_free() to free tpm chips Lino Sanfilippo
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