JDK-8256818 : SSLSocket that is never bound or connected leaks socket resources
  • Type: Bug
  • Component: security-libs
  • Sub-Component: javax.net.ssl
  • Affected Version: 8u271,11.0.9-oracle,13,15,16
  • Priority: P2
  • Status: Closed
  • Resolution: Fixed
  • Submitted: 2020-11-21
  • Updated: 2023-11-29
  • Resolved: 2020-12-02
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JDK 11 JDK 16 JDK 8 Other
11.0.11-oracleFixed 16 b27Fixed 8u271Fixed openjdk8u302Fixed
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There is a flaw in sun.security.ssl.SSLSocketImpl::close() which leads to leaking socket resources after JDK-8224829.

The close method calls duplexCloseOutput() and duplexCloseInput(). In case of an exception in any of these methods, the call to closeSocket() is bypassed, and the underlying Socket may not be closed.

This manifests in a real life leak after JDK-8224829 has introduced a call to getSoLinger() on the path of duplexCloseOutput -> closeNotify. If socket impl / OS socket hadn't been created yet it is done at that place. But then after duplexCloseOutput eventually fails with a SocketException since the socket wasn't connected, closing fails to call Socket::close().

This problem can be reproduced by this code:
		        SSLSocket sslSocket = (SSLSocket)SSLSocketFactory.getDefault().createSocket();

This is what happens when SSLContext.getDefault().getDefaultSSLParameters() is called, with close() being eventually called by the finalizer.
Fix Request (8u): Backport to 8u requested because it is a part of 8u291-oracle. Patch doesn't apply cleanly, review approval email: https://mail.openjdk.java.net/pipermail/jdk8u-dev/2021-April/013695.html Note: there is already a Fix Request filed for this backport, it is added to the backport issue [1]. AFAIU the recent changes to the process (please correct me if I am wrong), Fix Request needs to be filed in the main issue, so adding it here. [1] https://bugs.openjdk.java.net/browse/JDK-8259013?focusedCommentId=14413647&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-14413647

Fix Request (11u): Backport to 11u requested because it is a part of 11.0.11-oracle. Patch doesn't apply cleanly, review approval email: https://mail.openjdk.java.net/pipermail/jdk-updates-dev/2020-December/004508.html

Changeset: 93b6ab56 Author: Christoph Langer <clanger@openjdk.org> Date: 2020-12-02 19:23:26 +0000 URL: https://git.openjdk.java.net/jdk/commit/93b6ab56

Fix proposal: https://github.com/openjdk/jdk/pull/1363