Re: [PATCH 1/2] audit: fix NUL handling in untrusted strings

audit_string_contains_control() stops checking at the first NUL byte. If audit_string_contains_control() returns FALSE, audit_log_n_untrustedstring() submits the complete string - including the NUL byte and all following bytes, up to the specified maximum length - to audit_log_n_string(), which copies the data unchanged into the audit record. The audit record can thus contain a NUL byte (and some unchecked data after that). Because the user-space audit daemon treats audit records as NUL-terminated strings, an untrusted string that is shorter than the specified maximum length effectively terminates the audit record. This patch modifies audit_log_n_untrustedstring() to only log the data before the first NUL byte, if any.