Hi Roberto,
Sorry for the delay in reviewing these patches. Missing from this patch set is a cover letter with an explanation for grouping these patches into a patch set, other than for convenience. In this case, it would be along the lines that the original use case for EVM portable and immutable keys support was for a few critical files, not combined with an EVM encrypted key type. This patch set more fully integrates the initial EVM portable and immutable signature support.
On Thu, 2020-06-18 at 18:01 +0200, Roberto Sassu wrote:
evm_inode_init_security() requires the HMAC key to calculate the HMAC on initial xattrs provided by LSMs. Unfortunately, with the evm_key_loaded() check, the function continues even if the HMAC key is not loaded (evm_key_loaded() returns true also if EVM has been initialized only with a public key). If the HMAC key is not loaded, evm_inode_init_security() returns an error later when it calls evm_init_hmac().
Thus, this patch replaces the evm_key_loaded() check with a check of the EVM_INIT_HMAC flag in evm_initialized, so that evm_inode_init_security() returns 0 instead of an error.
Cc: stable@vger.kernel.org # 4.5.x Fixes: 26ddabfe96b ("evm: enable EVM when X509 certificate is loaded") Signed-off-by: Roberto Sassu roberto.sassu@huawei.com
Reviewed-by: Mimi Zohar zohar@linux.ibm.com
security/integrity/evm/evm_main.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c index 0d36259b690d..744c105b48d1 100644 --- a/security/integrity/evm/evm_main.c +++ b/security/integrity/evm/evm_main.c @@ -521,7 +521,8 @@ int evm_inode_init_security(struct inode *inode, struct evm_xattr *xattr_data; int rc;
- if (!evm_key_loaded() || !evm_protected_xattr(lsm_xattr->name))
- if (!(evm_initialized & EVM_INIT_HMAC) ||
!evm_protected_xattr(lsm_xattr->name))xattr_data = kzalloc(sizeof(*xattr_data), GFP_NOFS);