s390/zcrypt: Validate length in reply before using it

The length information in the reply is used to copy the key token to
the target buffer. An invalid information in t->len of the reply may
cause an over-read of the target buffer and also a over-write of the
target buffer. To prevent that, check t->len before using it.

As the available space in destination and source buffer is always
larger than the valid length value in the parameter block in the
reply, compare t->len with this (already validated) length
information. As a side effect, this check also prevents buffer
over-read and over-write.

Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

0 files changed, 0 insertions, 0 deletions