有些日志文件是用户和组？并且无法被 root 读取

Question

??????????  ? ?        ?            ?            ? syslog
-rw-r-----  1 syslog   adm        15K Sep  1  2014 syslog.1
??????????  ? ?        ?            ?            ? syslog.2.gz
-rw-r-----  1 syslog   adm       1,4K Aug 30  2014 syslog.3.gz
-rw-r-----  1 syslog   adm        69K Aug 29  2014 syslog.4.gz
-rw-r-----  1 syslog   adm       1,1K Aug 24  2014 syslog.5.gz
-rw-r-----  1 syslog   adm       1,5K Aug 23  2014 syslog.6.gz
-rw-r-----  1 syslog   adm       1,5K Aug 22  2014 syslog.7.gz

有人有线索吗？

/etc/rsyslog.conf

#
# Set the default permissions for all log files.
#
$FileOwner syslog
$FileGroup adm
$FileCreateMode 0640
$DirCreateMode 0755
$Umask 0022
$PrivDropToUser syslog
$PrivDropToGroup syslog