From: Jason Gunthorpe <jgg@ziepe.ca>
To: Stefan Berger <stefanb@linux.ibm.com>
Cc: Tyrel Datwyler <tyreld@linux.ibm.com>,
jarkko@kernel.org, peterhuewe@gmx.de,
linux-integrity@vger.kernel.org, Korrapati.Likhitha@ibm.com,
pavrampu@in.ibm.com, linux-kernel@vger.kernel.org,
linux-security-module@vger.kernel.org, gcwilson@us.ibm.com,
linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH] tpm: Fix kexec crash due to access to ops NULL pointer (powerpc)
Date: Mon, 20 Dec 2021 21:13:20 -0400 [thread overview]
Message-ID: <20211221011320.GM6467@ziepe.ca> (raw)
In-Reply-To: <d9eafa8f-4006-4bc2-c09b-6b02a14c6ef3@linux.ibm.com>
On Mon, Dec 20, 2021 at 08:05:58PM -0500, Stefan Berger wrote:
> diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
> index ddaeceb7e109..4cb908349b31 100644
> +++ b/drivers/char/tpm/tpm-chip.c
> @@ -473,15 +473,8 @@ static void tpm_del_char_device(struct tpm_chip *chip)
> mutex_unlock(&idr_lock);
>
> /* Make the driver uncallable. */
> - down_write(&chip->ops_sem);
> - if (chip->flags & TPM_CHIP_FLAG_TPM2) {
> - if (!tpm_chip_start(chip)) {
> - tpm2_shutdown(chip, TPM2_SU_CLEAR);
> - tpm_chip_stop(chip);
> - }
> - }
> - chip->ops = NULL;
> - up_write(&chip->ops_sem);
> + if (chip->ops)
ops cannot be read without locking
Jason
next prev parent reply other threads:[~2021-12-21 1:13 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-12 1:28 [PATCH] tpm: Fix kexec crash due to access to ops NULL pointer (powerpc) Stefan Berger
2021-12-20 5:17 ` Sachin Sant
2021-12-21 0:39 ` Tyrel Datwyler
2021-12-21 1:05 ` Stefan Berger
2021-12-21 1:13 ` Jason Gunthorpe [this message]
2021-12-21 1:31 ` Stefan Berger
2021-12-21 1:37 ` Tyrel Datwyler
2021-12-21 1:34 ` Tyrel Datwyler
2021-12-21 8:47 ` Jarkko Sakkinen
2021-12-21 14:01 ` Stefan Berger
2021-12-21 14:17 ` Stefan Berger
2021-12-29 0:10 ` Jarkko Sakkinen
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