linux-sg2042/security/integrity/evm
Dmitry Kasatkin 6d38ca01c0 evm: evm_verify_hmac must not return INTEGRITY_UNKNOWN
If EVM is not supported or enabled, evm_verify_hmac() returns
INTEGRITY_UNKNOWN, which ima_appraise_measurement() ignores and sets
the appraisal status based solely on the security.ima verification.

evm_verify_hmac() also returns INTEGRITY_UNKNOWN for other failures, such
as temporary failures like -ENOMEM, resulting in possible attack vectors.
This patch changes the default return code for temporary/unexpected
failures, like -ENOMEM, from INTEGRITY_UNKNOWN to INTEGRITY_FAIL, making
evm_verify_hmac() fail safe.

As a result, failures need to be re-evaluated in order to catch both
temporary errors, such as the -ENOMEM, as well as errors that have been
resolved in fix mode.

Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@nokia.com>
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
2011-07-18 12:29:48 -04:00
..
Kconfig evm: re-release 2011-07-18 12:29:40 -04:00
Makefile evm: re-release 2011-07-18 12:29:40 -04:00
evm.h evm: crypto hash replaced by shash 2011-07-18 12:29:46 -04:00
evm_crypto.c evm: crypto hash replaced by shash 2011-07-18 12:29:46 -04:00
evm_main.c evm: evm_verify_hmac must not return INTEGRITY_UNKNOWN 2011-07-18 12:29:48 -04:00
evm_secfs.c evm: re-release 2011-07-18 12:29:40 -04:00