| Message ID | 20220506123145.229058-1-stefan.mahnke-hartmann@infineon.com |
|---|---|
| State | New |
| Headers | show |
| Series | [1/2] tpm: Fix buffer access in tpm2_get_tpm_pt() | expand |
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;
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(-)