linux/security/integrity
THOBY Simon 8ecd39cb61 IMA: prevent SETXATTR_CHECK policy rules with unavailable algorithms
SETXATTR_CHECK policy rules assume that any algorithm listed in the
'appraise_algos' flag must be accepted when performing setxattr() on
the security.ima xattr.  However nothing checks that they are
available in the current kernel.  A userland application could hash
a file with a digest that the kernel wouldn't be able to verify.
However, if SETXATTR_CHECK is not in use, the kernel already forbids
that xattr write.

Verify that algorithms listed in appraise_algos are available to the
current kernel and reject the policy update otherwise. This will fix
the inconsistency between SETXATTR_CHECK and non-SETXATTR_CHECK
behaviors.

That filtering is only performed in ima_parse_appraise_algos() when
updating policies so that we do not have to pay the price of
allocating a hash object every time validate_hash_algo() is called
in ima_inode_setxattr().

Signed-off-by: THOBY Simon <Simon.THOBY@viveris.fr>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2021-08-16 17:35:35 -04:00
..
evm evm: Check xattr size discrepancy between kernel and user 2021-06-21 08:34:21 -04:00
ima IMA: prevent SETXATTR_CHECK policy rules with unavailable algorithms 2021-08-16 17:35:35 -04:00
platform_certs integrity: Load mokx variables into the blacklist keyring 2021-03-11 16:34:48 +00:00
digsig_asymmetric.c ima: Support EC keys for signature verification 2021-03-26 19:41:59 +11:00
digsig.c ima: enable loading of build time generated key on .ima keyring 2021-04-09 10:40:20 -04:00
iint.c evm: Load EVM key in ima_load_x509() to avoid appraisal 2021-05-21 12:47:04 -04:00
integrity_audit.c integrity: Use current_uid() in integrity_audit_message() 2020-08-31 17:46:50 -04:00
integrity.h crypto: sha - split sha.h into sha1.h and sha2.h 2020-11-20 14:45:33 +11:00
Kconfig powerpc: Load firmware trusted keys/hashes into kernel keyring 2019-11-13 00:33:23 +11:00
Makefile powerpc: Load firmware trusted keys/hashes into kernel keyring 2019-11-13 00:33:23 +11:00