[FELIX-6318] Tiny thread-safety bug in BundleWiringImpl

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: framework-6.0.3, framework-5.6.12
• Fix Version/s: framework-6.0.4
• Component/s: Framework
• Assignee: Jean-Baptiste Onofré
• Reporter: Richard Hernandez
• Created: 07/Aug/20 22:10
• Updated: 15/Dec/20 22:11
• Resolved: 16/Sep/20 16:00

Description

In BundleWiringImple::getClassLoaderInternal, you're using double-checked locking to access the field m_classLoader. However, you're not using it entirely correctly. The current code assigns the volatile field to a local variable, null-checks the volatile field, and returns the local variable if the second read of the volatile field is not null. While highly improbable, it's possible for the first read of the volatile variable to be null and the second read to not be. This would cause `BundleWiringImpl::getClassLoader` to return null.

 

See https://github.com/apache/felix-dev/blob/master/framework/src/main/java/org/apache/felix/framework/BundleWiringImpl.java#L713-L717

Issue Links

• links to: GitHub Pull Request #41