| Message ID | 20220513134152.270442-1-stefan.mahnke-hartmann@infineon.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2,1/2] tpm: Fix buffer access in tpm2_get_tpm_pt() | expand |
On Fri, May 13, 2022 at 03:41:51PM +0200, Stefan Mahnke-Hartmann wrote: > 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> > --- > Changelog: > * v2: > * Add inline comment to indicate the root cause to may access unitilized > memory. > * Change 'field upgrade mode' to lower case. > > drivers/char/tpm/tpm2-cmd.c | 11 ++++++++++- > 1 file changed, 10 insertions(+), 1 deletion(-) > > diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c > index 4704fa553098..04a3e23a4afc 100644 > --- a/drivers/char/tpm/tpm2-cmd.c > +++ b/drivers/char/tpm/tpm2-cmd.c > @@ -400,7 +400,16 @@ 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); > + /* > + * To prevent failing boot up of some systems, Infineon TPM2.0 > + * returns SUCCESS on TPM2_Startup in field upgrade mode. Also > + * the TPM2_Getcapability command returns a zero length list > + * in field upgrade mode. > + */ > + 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 > Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org> BR, Jarkko
diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c index 4704fa553098..04a3e23a4afc 100644 --- a/drivers/char/tpm/tpm2-cmd.c +++ b/drivers/char/tpm/tpm2-cmd.c @@ -400,7 +400,16 @@ 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); + /* + * To prevent failing boot up of some systems, Infineon TPM2.0 + * returns SUCCESS on TPM2_Startup in field upgrade mode. Also + * the TPM2_Getcapability command returns a zero length list + * in field upgrade mode. + */ + 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> --- Changelog: * v2: * Add inline comment to indicate the root cause to may access unitilized memory. * Change 'field upgrade mode' to lower case. drivers/char/tpm/tpm2-cmd.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-)