If filesystem is mounted read-only or file is immutable, updating xattr will fail. This is a usual case during early boot until filesystem is remount read-write. This patch verifies conditions to skip unnecessary attempt to calculate HMAC and set xattr.
Changes in v2: * indention changed according to Lindent (requested by Mimi) Signed-off-by: Dmitry Kasatkin <[email protected]> --- security/integrity/evm/evm_main.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c index 9685af3..b392fe6 100644 --- a/security/integrity/evm/evm_main.c +++ b/security/integrity/evm/evm_main.c @@ -162,9 +162,14 @@ static enum integrity_status evm_verify_hmac(struct dentry *dentry, (const char *)xattr_data, xattr_len, calc.digest, sizeof(calc.digest)); if (!rc) { - /* we probably want to replace rsa with hmac here */ - evm_update_evmxattr(dentry, xattr_name, xattr_value, - xattr_value_len); + /* Replace RSA with HMAC if not mounted readonly and + * not immutable + */ + if (!IS_RDONLY(dentry->d_inode) && + !IS_IMMUTABLE(dentry->d_inode)) + evm_update_evmxattr(dentry, xattr_name, + xattr_value, + xattr_value_len); } break; default: -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
