tpm: st33zp24: fix potential buffer overruns caused by bit glitches on the bus
authorJeremy Boone <jeremy.boone@nccgroup.trust>
Thu, 8 Feb 2018 20:29:09 +0000 (12:29 -0800)
committerJames Morris <james.morris@microsoft.com>
Mon, 26 Feb 2018 23:43:45 +0000 (15:43 -0800)
commit6d24cd186d9fead3722108dec1b1c993354645ff
tree5af252ce6f3ad83f5efe1cf043027534421a3d92
parent9b8cb28d7c62568a5916bdd7ea1c9176d7f8f2ed
tpm: st33zp24: fix potential buffer overruns caused by bit glitches on the bus

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>
drivers/char/tpm/st33zp24/st33zp24.c