Merge branch 'next-tpm' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security

Pull tpm updates from James Morris:

 - Clean up the transmission flow

   Cleaned up the whole transmission flow. Locking of the chip is now
   done in the level of tpm_try_get_ops() and tpm_put_ops() instead
   taking the chip lock inside tpm_transmit(). The nested calls inside
   tpm_transmit(), used with the resource manager, have been refactored
   out.

   Should make easier to perform more complex transactions with the TPM
   without making the subsystem a bigger mess (e.g. encrypted channel
   patches by James Bottomley).

 - PPI 1.3 support

   TPM PPI 1.3 introduces an additional optional command parameter that
   may be needed for some commands. Display the parameter if the command
   requires such a parameter. Only command 23 (SetPCRBanks) needs one.

   The PPI request file will show output like this then:

      # echo "23 16" > request
      # cat request
      23 16

      # echo "5" > request
      # cat request
      5

 - Extend all PCR banks in IMA

   Instead of static PCR banks array, the array of available PCR banks
   is now allocated dynamically. The digests sizes are determined
   dynamically using a probe PCR read without relying crypto's static
   list of hash algorithms.

   This should finally make sealing of measurements in IMA safe and
   secure.

 - TPM 2.0 selftests

   Added a test suite to tools/testing/selftests/tpm2 previously outside
   of the kernel tree: https://github.com/jsakkine-intel/tpm2-scripts

* 'next-tpm' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (37 commits)
  tpm/ppi: Enable submission of optional command parameter for PPI 1.3
  tpm/ppi: Possibly show command parameter if TPM PPI 1.3 is used
  tpm/ppi: Display up to 101 operations as define for version 1.3
  tpm/ppi: rename TPM_PPI_REVISION_ID to TPM_PPI_REVISION_ID_1
  tpm/ppi: pass function revision ID to tpm_eval_dsm()
  tpm: pass an array of tpm_extend_digest structures to tpm_pcr_extend()
  KEYS: trusted: explicitly use tpm_chip structure from tpm_default_chip()
  tpm: move tpm_chip definition to include/linux/tpm.h
  tpm: retrieve digest size of unknown algorithms with PCR read
  tpm: rename and export tpm2_digest and tpm2_algorithms
  tpm: dynamically allocate the allocated_banks array
  tpm: remove @flags from tpm_transmit()
  tpm: take TPM chip power gating out of tpm_transmit()
  tpm: introduce tpm_chip_start() and tpm_chip_stop()
  tpm: remove TPM_TRANSMIT_UNLOCKED flag
  tpm: use tpm_try_get_ops() in tpm-sysfs.c.
  tpm: remove @space from tpm_transmit()
  tpm: move TPM space code out of tpm_transmit()
  tpm: move tpm_validate_commmand() to tpm2-space.c
  tpm: clean up tpm_try_transmit() error handling flow
  ...

1 files changed, 16 insertions, 6 deletions

diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
index 36952ef98f90..763fc7e6c005 100644
--- a/drivers/char/tpm/tpm_crb.c
+++ b/drivers/char/tpm/tpm_crb.c
@@ -287,19 +287,29 @@ static int crb_recv(struct tpm_chip *chip, u8 *buf, size_t count)
 	struct crb_priv *priv = dev_get_drvdata(&chip->dev);
 	unsigned int expected;
 
-	/* sanity check */
-	if (count < 6)
+	/* A sanity check that the upper layer wants to get at least the header
+	 * as that is the minimum size for any TPM response.
+	 */
+	if (count < TPM_HEADER_SIZE)
 		return -EIO;
 
+	/* If this bit is set, according to the spec, the TPM is in
+	 * unrecoverable condition.
+	 */
 	if (ioread32(&priv->regs_t->ctrl_sts) & CRB_CTRL_STS_ERROR)
 		return -EIO;
 
-	memcpy_fromio(buf, priv->rsp, 6);
-	expected = be32_to_cpup((__be32 *) &buf[2]);
-	if (expected > count || expected < 6)
+	/* Read the first 8 bytes in order to get the length of the response.
+	 * We read exactly a quad word in order to make sure that the remaining
+	 * reads will be aligned.
+	 */
+	memcpy_fromio(buf, priv->rsp, 8);
+
+	expected = be32_to_cpup((__be32 *)&buf[2]);
+	if (expected > count || expected < TPM_HEADER_SIZE)
 		return -EIO;
 
-	memcpy_fromio(&buf[6], &priv->rsp[6], expected - 6);
+	memcpy_fromio(&buf[8], &priv->rsp[8], expected - 8);
 
 	return expected;
 }