NPE in case of an SQLException to be thrown on checkOpen() in DelegatingConnection

• Key: DBCP-241
• Type: Bug
• Status: Closed
• Resolution: Fixed
• Priority: Major
• Assignee: Unassigned
• Reporter: Jörg Heinicke
• Affects Version/s: 1.2.2
• Fix Version/s: 1.3

Description

I only got it from the Spring forums (http://forum.springframework.org/showthread.php?t=44068). I have no idea which version or if it is already fixed. It should be easy to review.

Stacktrace:

java.lang.NullPointerException
at org.apache.commons.dbcp.PoolingConnection.toString(PoolingConnection.java:248)
at java.lang.String.valueOf(String.java:2615)
at java.lang.StringBuffer.append(StringBuffer.java:220)
at org.apache.commons.dbcp.DelegatingConnection.checkOpen(DelegatingConnection.java:354)
at org.apache.commons.dbcp.DelegatingConnection.prepareStatement(DelegatingConnection.java:246)
at org.apache.commons.dbcp.PoolingDataSource$PoolGuardConnectionWrapper.prepareStatement(PoolingDataSource.java:302)
at org.hibernate.jdbc.AbstractBatcher.getPreparedStatement(AbstractBatcher.java:505)
at org.hibernate.jdbc.AbstractBatcher.getPreparedStatement(AbstractBatcher.java:423)
at org.hibernate.jdbc.AbstractBatcher.prepareQueryStatement(AbstractBatcher.java:139)

implementation of the method:

protected void checkOpen() throws SQLException {
if(_closed) { throw new SQLException ("Connection " + _conn + " is closed."); }
}

Regards

Joerg

Comments

[Phil Steitz]

Thanks for reporting this bug, which is a regression in 1.2.2 from DBCP-187.

[Phil Steitz]

The following code reproduces this bug using DBCP 1.2.2:
conn = new DelegatingConnection( new PoolingConnection
(delegateConn2, new GenericKeyedObjectPool()));
try { conn.close(); } catch (Exception ex) {}
conn.prepareStatement("");

The NPE is generated by this line in PoolingConnection.toString:
return "PoolingConnection: " + _pstmtPool.toString();

The DBCP-187 change to checkOpen in DelegatingException exposed this NPE vulnerability in PoolingConnection. Others exist in this class as well and all should be fixed before this bug is closed.

To avoid this and other NPEs, DBCP 1.x users should avoid calling prepareStatement methods on closed PoolingConnections.

[Phil Steitz]

s/DelegatingException/DelegatingConnection in last comment.

[Phil Steitz]

Fixed in r 578597.