From: Stefan Mahnke-Hartmann <stefan.mahnke-hartmann@infineon.com>
To: <jarkko@kernel.org>, <linux-integrity@vger.kernel.org>,
<linux-kernel@vger.kernel.org>
Cc: <Marten.Lindahl@axis.com>, <martenli@axis.com>, <jgg@ziepe.ca>,
<jsnitsel@redhat.com>, <nayna@linux.vnet.ibm.com>,
<johannes.holland@infineon.com>, <peterhuewe@gmx.de>,
Stefan Mahnke-Hartmann <stefan.mahnke-hartmann@infineon.com>,
<stable@vger.kernel.org>
Subject: [PATCH 1/2] tpm: Fix buffer access in tpm2_get_tpm_pt()
Date: Fri, 6 May 2022 14:31:46 +0200 [thread overview]
Message-ID: <20220506123145.229058-1-stefan.mahnke-hartmann@infineon.com> (raw)
Under certain conditions uninitialized memory will be accessed.
As described by TCG Trusted Platform Module Library Specification,
rev. 1.59 (Part 3: Commands), if a TPM2_GetCapability is received,
requesting a capability, the TPM in Field Upgrade mode may return a
zero length list.
Check the property count in tpm2_get_tpm_pt().
Fixes: 2ab3241161b3 ("tpm: migrate tpm2_get_tpm_pt() to use struct tpm_buf")
Cc: stable@vger.kernel.org
Signed-off-by: Stefan Mahnke-Hartmann <stefan.mahnke-hartmann@infineon.com>
---
drivers/char/tpm/tpm2-cmd.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
index 4704fa553098..e62a644ce26b 100644
--- a/drivers/char/tpm/tpm2-cmd.c
+++ b/drivers/char/tpm/tpm2-cmd.c
@@ -400,7 +400,10 @@ ssize_t tpm2_get_tpm_pt(struct tpm_chip *chip, u32 property_id, u32 *value,
if (!rc) {
out = (struct tpm2_get_cap_out *)
&buf.data[TPM_HEADER_SIZE];
- *value = be32_to_cpu(out->value);
+ if (be32_to_cpu(out->property_cnt) > 0)
+ *value = be32_to_cpu(out->value);
+ else
+ rc = -ENODATA;
}
tpm_buf_destroy(&buf);
return rc;
--
2.25.1
next reply other threads:[~2022-05-06 12:33 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-06 12:31 Stefan Mahnke-Hartmann [this message]
2022-05-07 19:43 ` [PATCH 1/2] tpm: Fix buffer access in tpm2_get_tpm_pt() Jarkko Sakkinen
2022-05-09 11:48 ` Stefan Mahnke-Hartmann
2022-05-11 15:11 ` Jarkko Sakkinen
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