PK63006: WIN - CRASH IN NTDLL.DLL

APAR status

• Closed as program error.

Error description

• Error Message: Customer was experiencing crash ntdll.dll
  RtlEnterCriticalSection.
  .
  Stack Trace: Follwing was the current thread details from jdump
  o/p :-
  MEMORY ACCESS ERROR  in  ntdll.dll
  
  (ip)=77F8206B  at  ntdll.dll  RtlEnterCriticalSection + 000B
  
  (ip)=4B1327D1  at  ODBC32.dll  ODBC32.dll + 27D1
  
  (ip)=4B1327EB  at  ODBC32.dll  ODBC32.dll + 27EB
  
  (ip)=4B13A697  at  ODBC32.dll  SQLCancel + 15A8
  
  (ip)=4B13A770  at  ODBC32.dll  SQLAllocConnect + 0019
  
  (ip)=4B121060  at  JdbcOdbc.dll
  
                     _Java_sun_jdbc_odbc_JdbcOdbc_allocConnect@16
  + 0030
  (cc)=4AEB6E55  at  sun/jdbc/odbc/JdbcOdbc.allocConnect
  (I<OSB>B)I  native
  (pc)=48254D04  at  sun/jdbc/odbc/JdbcOdbc.SQLAllocConnect  (I)I
  
  (ip)=4393E056  at  jitc.dll  _InvokeInterpreterFromJIT + 009C
  
  (cc)=0233A74C  at  sun/jdbc/odbc/JdbcOdbcConnection.initialize
  
  (pc)=48243EAB  at  sun/jdbc/odbc/JdbcOdbcDriver.connect
  
  (pc)=47E59C46  at  java/sql/DriverManager.getConnection
  
  (pc)=47E597E9  at  java/sql/DriverManager.getConnection
  
  (pc)=48241C8F  at
  com/gtech/connector/oag/OagClient.createConnection
  (pc)=48241AC8  at
  com/gtech/connector/oag/OagClient.getConnection
  .
  

Local fix

Problem summary

• As the crash was happening in ODBC32.dll we asked the customer
  to involve Microsoft in this issue and figured out that one of
  the argument hEnv is getting corrupted. So narrowed down the
  area of code and found that the bug lies in
  JdbcOdbcDriver.connect().
  Following was the scenerio because of which we were
  experiencing the crash :-
  1) T1 is getting finished with its work on a connection C1 and
  calls C1.close() where C1 is an instance of type
  JdbcOdbcConnection. As part of close connection it calls the
  JdbcOdbcDriver.closeConnection(). Note that this method is not
  marked as synchronized. This method checks to see if this is the
  last connection and since no other connections are currently
  active, it will call SQLFreeEnv. But before it has called
  SQLFreeEnv and set a global variable hEnv to NULL, thread T2 has
  called  JdbcOdbcDriver.connect() and done a check for this
  variable and finds that it is not NULL which will make it think
  a valid hEnv will exist. Thread T1 continues and calls
  SQLFreeEnv() which releases the OpenRDA ODBC driver DLL.
  
  2) T2 needs a new connection so it calls
  java/sql/DriverManager.getConnection which in turn calls the
  connect() method of the JdbcOdbcDriver class. The connect()
  method checks to see if hEnv is NULL. If it is not then it will
  not allocate a new hEnv because it assumes one already exists.
  But this is not true in this case because T1 has released it.
  T2 then goes on to call the SQLAllocConnect() call and passes in
  the hEnv environment variable which has already been freed. This
  causes the ODBC driver manager to crash.
  

Problem conclusion

• This defect will be fixed in:
  1.4.2 SR11
  .
  Synchronized the methods who were causing the problem.
  .
  To obtain the fix:
  Install build 20080615 or later
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

Fix information

• Fixed component name

  JAVA(1.3/1.4 CO

• Fixed component ID

  5648C9800

Applicable component levels

• R42A PSN

     UP

• R42L PSN

     UP

• R42W PSN

     UP

• R420 PSN

     UP