Updated from 2.318 to 2.326. After update Jenkins can not install the new remoting.jar file.

The file shows permissions as  

1. ls -l remoting.jar
   rw-rr- 1 root root 1522173 Dec 27 13:55 remoting.jar
2. If I delete the file remoting.jar then the file is deployed and the agent is started.
3. Rebooting Jenkins or if the Agent stops it can not deploy the file and restart the agent so that all commands fails to the node including SSH connections.

USER=root
[12/27/21 14:52:15] [SSH] Starting sftp client.
[12/27/21 14:52:15] [SSH] Copying latest remoting.jar...
java.io.IOException: Could not copy remoting.jar into '/admin' on agent
at hudson.plugins.sshslaves.SSHLauncher.copyAgentJar(SSHLauncher.java:717)
at hudson.plugins.sshslaves.SSHLauncher.access$300(SSHLauncher.java:113)
at hudson.plugins.sshslaves.SSHLauncher$1.call(SSHLauncher.java:457)
at hudson.plugins.sshslaves.SSHLauncher$1.call(SSHLauncher.java:423)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.IllegalArgumentException: invalid len argument
at com.trilead.ssh2.SFTPv3Client.read(SFTPv3Client.java:1232)
at com.trilead.ssh2.jenkins.SFTPClient$SFTPInputStream.read(SFTPClient.java:172)
at com.google.common.io.ByteStreams.toByteArrayInternal(ByteStreams.java:184)
at com.google.common.io.ByteStreams.toByteArray(ByteStreams.java:224)
at hudson.plugins.sshslaves.SSHLauncher.readInputStreamIntoByteArrayAndClose(SSHLauncher.java:775)
at hudson.plugins.sshslaves.SSHLauncher.copyAgentJar(SSHLauncher.java:686)
... 7 more
[12/27/21 14:52:15] Launch failed - cleaning up connection

Remove the file on the node.

#rm remoting.jar

From Jenkins restart the Agent on the node,

USER=root
[12/27/21 14:53:52] [SSH] Starting sftp client.
[12/27/21 14:53:52] [SSH] Copying latest remoting.jar...
[12/27/21 14:53:52] [SSH] Copied 1,522,173 bytes.
Expanded the channel window size to 4MB
[12/27/21 14:53:52] [SSH] Starting agent process: cd "/admin" && /usr/java8_64/jre/bin/java -jar remoting.jar -workDir /export/nim -jar-cache /export/nim/remoting/jarCache
Dec 27, 2021 2:53:54 PM org.jenkinsci.remoting.engine.WorkDirManager initializeWorkDir
INFO: Using /export/nim/remoting as a remoting work directory
Dec 27, 2021 2:53:54 PM org.jenkinsci.remoting.engine.WorkDirManager setupLogging
INFO: Both error and output logs will be printed to /export/nim/remoting
<===[JENKINS REMOTING CAPACITY]===>channel started
Remoting version: 4.11.2
This is a Unix agent
Evacuated stdout
Agent successfully connected and online