tpm: 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.  If a bit does
flip it could cause an overrun if it's in one of the size parameters,
so sanity check that we're not overrunning the provided buffer when
doing a memcpy().

Signed-off-by: Jeremy Boone <>
Signed-off-by: James Bottomley <>
Reviewed-by: Jarkko Sakkinen <>
Tested-by: Jarkko Sakkinen <>
Signed-off-by: Jarkko Sakkinen <>
Signed-off-by: James Morris <>
2 files changed