Re: [PATCH] tpm: do handle area size validation only when TPM space used

[Jarkko Sakkinen]

On Tue, Mar 28, 2017 at 11:27:53AM +0000, Alexander.Steffen@xxxxxxxxxxxx wrote:
> Yes, this fixes the issue for me. Thanks.
> 
> Alexander

Great. I will squash this to the infrastructure patch. Thank you.

/Jarkko

> > -----Original Message-----
> > From: Jarkko Sakkinen [mailto:jarkko.sakkinen@xxxxxxxxxxxxxxx]
> > Sent: Tuesday, March 28, 2017 12:25 PM
> > To: Steffen Alexander (IFAG CCS ESS D SW A)
> > Cc: tpmdd-devel@xxxxxxxxxxxxxxxxxxxxx; linux-security-
> > module@xxxxxxxxxxxxxxx; Peter Huewe; Marcel Selhorst; Jason Gunthorpe;
> > open list
> > Subject: Re: [PATCH] tpm: do handle area size validation only when TPM
> > space used
> > 
> > So do you need this or not?
> > 
> > /Jarkko
> > 
> > On Mon, Mar 27, 2017 at 12:08:15AM +0300, Jarkko Sakkinen wrote:
> > > In order to not cause backwards compatibility issues with
> > > /dev/tpm0 disable handle area size validation if tpm_transmit is not
> > > called with a TPM space.
> > >
> > > Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxx>
> > > ---
> > >  drivers/char/tpm/tpm-interface.c | 9 +++++++--
> > >  1 file changed, 7 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/drivers/char/tpm/tpm-interface.c
> > > b/drivers/char/tpm/tpm-interface.c
> > > index bf0c3fa..158c1db 100644
> > > --- a/drivers/char/tpm/tpm-interface.c
> > > +++ b/drivers/char/tpm/tpm-interface.c
> > > @@ -328,7 +328,9 @@ unsigned long tpm_calc_ordinal_duration(struct
> > > tpm_chip *chip,  }  EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration);
> > >
> > > -static bool tpm_validate_command(struct tpm_chip *chip, const u8
> > > *cmd,
> > > +static bool tpm_validate_command(struct tpm_chip *chip,
> > > +				 struct tpm_space *space,
> > > +				 const u8 *cmd,
> > >  				 size_t len)
> > >  {
> > >  	const struct tpm_input_header *header = (const void *)cmd; @@ -
> > 340,6
> > > +342,9 @@ static bool tpm_validate_command(struct tpm_chip *chip,
> > const u8 *cmd,
> > >  	if (len < TPM_HEADER_SIZE)
> > >  		return false;
> > >
> > > +	if (!space)
> > > +		return true;
> > > +
> > >  	if (chip->flags & TPM_CHIP_FLAG_TPM2 && chip->nr_commands) {
> > >  		cc = be32_to_cpu(header->ordinal);
> > >
> > > @@ -386,7 +391,7 @@ ssize_t tpm_transmit(struct tpm_chip *chip, struct
> > tpm_space *space,
> > >  	unsigned long stop;
> > >  	bool need_locality;
> > >
> > > -	if (!tpm_validate_command(chip, buf, bufsiz))
> > > +	if (!tpm_validate_command(chip, space, buf, bufsiz))
> > >  		return -EINVAL;
> > >
> > >  	if (bufsiz > TPM_BUFSIZE)
> > > --
> > > 2.9.3
> > >
>