tpm_i2c_infineon: fix potential buffer overruns caused by bit glitches on the bus
authorJeremy Boone <jeremy.boone@nccgroup.trust>
Thu, 8 Feb 2018 20:30:01 +0000 (12:30 -0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 9 Mar 2018 06:41:00 +0000 (22:41 -0800)
commite9951ab03f51a349160167794deb82d1f6e258af
tree87304b1d6849e0e3af2dfbe04e1ac432e648472a
parent648b62fda1a35c9198689cca76ace580a67e7872
tpm_i2c_infineon: fix potential buffer overruns caused by bit glitches on the bus

commit 9b8cb28d7c62568a5916bdd7ea1c9176d7f8f2ed upstream.

Discrete TPMs are often connected over slow serial buses which, on
some platforms, can have glitches causing bit flips.  In all the
driver _recv() functions, we need to use a u32 to unmarshal the
response size, otherwise a bit flip of the 31st bit would cause the
expected variable to go negative, which would then try to read a huge
amount of data.  Also sanity check that the expected amount of data is
large enough for the TPM header.

Signed-off-by: Jeremy Boone <jeremy.boone@nccgroup.trust>
Cc: stable@vger.kernel.org
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: James Morris <james.morris@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/char/tpm/tpm_i2c_infineon.c