Oracle BUG导致实例宕机：ORA-07445

现象：
客户的数据库（RAC环境：11.1.0.6）发生了实例异常宕机现象，伴随有ORA-07445错误：
Sun Jun 23 01:00:06 2013
Exception [type: SIGSEGV, Address not mapped to object] [ADDR:0xF] [PC:0x755773D, kcbw_get_bh()+67]
Errors in file /oracle/app/11gR1/diag/rdbms/xij/xij1/trace/xij1_mman_2015.trc (incident=298938):
ORA-07445: exception encountered: core dump [kcbw_get_bh()+67] [SIGSEGV] [ADDR:0xF] [PC:0x755773D] [Address not mapped to object] []
Incident details in: /oracle/app/11gR1/diag/rdbms/xij/xij1/incident/incdir_298938/xij1_mman_2015_i298938.trc
Sun Jun 23 01:00:07 2013
Trace dumping is performing id=[cdmp_20130623010007]
Sun Jun 23 01:00:09 2013
Sweep Incident[298938]: completed
Sun Jun 23 01:00:09 2013
Errors in file /oracle/app/11gR1/diag/rdbms/xij/xij1/trace/xij1_pmon_1981.trc:
ORA-00822: MMAN process terminated with error
PMON (ospid: 1981): terminating the instance due to error 822
Sun Jun 23 01:00:09 2013
Errors in file /oracle/app/11gR1/diag/rdbms/xij/xij1/trace/xij1_j000_22268.trc:
ORA-00822: MMAN process terminated with error
Sun Jun 23 01:00:09 2013
Errors in file /oracle/app/11gR1/diag/rdbms/xij/xij1/trace/xij1_m000_22430.trc:
ORA-00822: MMAN process terminated with error
System state dump is made for local instance
System State dumped to trace file /oracle/app/11gR1/diag/rdbms/xij/xij1/trace/xij1_diag_1987.trc
Sun Jun 23 01:00:09 2013
ORA