Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Message-ID: <204a438b6db54060d03689389d6663b0d4ca815d.camel@kernel.org>
Subject: Re: [PATCH] tpm: fix potential NULL pointer access in
 tpm_del_char_device()
From:   Jarkko Sakkinen <jarkko@kernel.org>
To:     Lino Sanfilippo <LinoSanfilippo@gmx.de>, peterhuewe@gmx.de,
        jgg@ziepe.ca
Cc:     p.rosenberger@kunbus.com, linux-integrity@vger.kernel.org,
        linux-kernel@vger.kernel.org, stable@vger.kernel.org
Date:   Mon, 13 Sep 2021 23:25:40 +0300
In-Reply-To: <20210910180451.19314-1-LinoSanfilippo@gmx.de>
References: <20210910180451.19314-1-LinoSanfilippo@gmx.de>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
User-Agent: Evolution 3.36.5-0ubuntu1 
MIME-Version: 1.0
Precedence: bulk

On Fri, 2021-09-10 at 20:04 +0200, Lino Sanfilippo wrote:
> In tpm_del_char_device() make sure that chip->ops is still valid.
> This check is needed since in case of a system shutdown
> tpm_class_shutdown() has already been called and set chip->ops to NULL.
> This leads to a NULL pointer access as soon as tpm_del_char_device()
> tries to access chip->ops in case of TPM 2.
>=20
> Fixes: dcbeab1946454 ("tpm: fix crash in tpm_tis deinitialization")
> Cc: stable@vger.kernel.org
> Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
> ---

Have you been able to reproduce this in some environment?

/Jarkko