(ITS#4872) Non-portable comparison in wait4msg() (result.c) causes infinite loop

Full_Name: Carsten Agger Version: 2.3.20 OS: OSE URL: ftp://ftp.openldap.org/incoming/ Submission from: (NULL) (194.237.142.21)

On our architecture (OSE running on an AXE processor), time_t is an unsigned int.

This means that this code, as found in the wait4msg function in libraries/libldap/result.c, will break:

  if ( rc == LDAP_MSG_X_KEEP_LOOKING && tvp != NULL ) {
                  tmp_time = time( NULL );
                  tv0.tv_sec -= ( tmp_time - start_time );
                  if ( tv0.tv_sec <= 0 ) {
                          rc = 0; /* timed out */
                          ld->ld_errno = LDAP_TIMEOUT;
                          break;
                  }
                  tv.tv_sec = tv0.tv_sec;
                    ...
      }

Why? Because if (start_time > tmp_time), the condition ( tv0.tv_sec <= 0 ) will never evaluate to TRUE, and the break will never be executed - yielding an infinite loop.

Solution: rewrite in a portable way, e.g. (as suggested by Pierangelo Masarati on the bugs mailing list) by testing if the value of tv_sec would be negative after subtracting ( tmp_time - start_time ) before assigning it.