diff options
Diffstat (limited to 'security/integrity/evm/evm_main.c')
| -rw-r--r-- | security/integrity/evm/evm_main.c | 29 |
1 files changed, 19 insertions, 10 deletions
diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c index ba8615576d4d..976b8dce6496 100644 --- a/security/integrity/evm/evm_main.c +++ b/security/integrity/evm/evm_main.c @@ -29,7 +29,7 @@ int evm_initialized; static char *integrity_status_msg[] = { - "pass", "fail", "no_label", "no_xattrs", "unknown" + "pass", "pass_immutable", "fail", "no_label", "no_xattrs", "unknown" }; char *evm_hmac = "hmac(sha1)"; char *evm_hash = "sha1"; @@ -118,7 +118,8 @@ static enum integrity_status evm_verify_hmac(struct dentry *dentry, enum integrity_status evm_status = INTEGRITY_PASS; int rc, xattr_len; - if (iint && iint->evm_status == INTEGRITY_PASS) + if (iint && (iint->evm_status == INTEGRITY_PASS || + iint->evm_status == INTEGRITY_PASS_IMMUTABLE)) return iint->evm_status; /* if status is not PASS, try to check again - against -ENOMEM */ @@ -155,22 +156,26 @@ static enum integrity_status evm_verify_hmac(struct dentry *dentry, rc = -EINVAL; break; case EVM_IMA_XATTR_DIGSIG: + case EVM_XATTR_PORTABLE_DIGSIG: rc = evm_calc_hash(dentry, xattr_name, xattr_value, - xattr_value_len, calc.digest); + xattr_value_len, xattr_data->type, + calc.digest); if (rc) break; rc = integrity_digsig_verify(INTEGRITY_KEYRING_EVM, (const char *)xattr_data, xattr_len, calc.digest, sizeof(calc.digest)); if (!rc) { - /* Replace RSA with HMAC if not mounted readonly and - * not immutable - */ - if (!IS_RDONLY(d_backing_inode(dentry)) && - !IS_IMMUTABLE(d_backing_inode(dentry))) + if (xattr_data->type == EVM_XATTR_PORTABLE_DIGSIG) { + if (iint) + iint->flags |= EVM_IMMUTABLE_DIGSIG; + evm_status = INTEGRITY_PASS_IMMUTABLE; + } else if (!IS_RDONLY(d_backing_inode(dentry)) && + !IS_IMMUTABLE(d_backing_inode(dentry))) { evm_update_evmxattr(dentry, xattr_name, xattr_value, xattr_value_len); + } } break; default: @@ -271,7 +276,7 @@ static enum integrity_status evm_verify_current_integrity(struct dentry *dentry) * affect security.evm. An interesting side affect of writing posix xattr * acls is their modifying of the i_mode, which is included in security.evm. * For posix xattr acls only, permit security.evm, even if it currently - * doesn't exist, to be updated. + * doesn't exist, to be updated unless the EVM signature is immutable. */ static int evm_protect_xattr(struct dentry *dentry, const char *xattr_name, const void *xattr_value, size_t xattr_value_len) @@ -339,7 +344,8 @@ int evm_inode_setxattr(struct dentry *dentry, const char *xattr_name, if (strcmp(xattr_name, XATTR_NAME_EVM) == 0) { if (!xattr_value_len) return -EINVAL; - if (xattr_data->type != EVM_IMA_XATTR_DIGSIG) + if (xattr_data->type != EVM_IMA_XATTR_DIGSIG && + xattr_data->type != EVM_XATTR_PORTABLE_DIGSIG) return -EPERM; } return evm_protect_xattr(dentry, xattr_name, xattr_value, @@ -416,6 +422,9 @@ void evm_inode_post_removexattr(struct dentry *dentry, const char *xattr_name) /** * evm_inode_setattr - prevent updating an invalid EVM extended attribute * @dentry: pointer to the affected dentry + * + * Permit update of file attributes when files have a valid EVM signature, + * except in the case of them having an immutable portable signature. */ int evm_inode_setattr(struct dentry *dentry, struct iattr *attr) { |