RFR(XS): 8057564: JVM hangs at getAgentProperties after attaching to VM with lower IntegrityLevel

[Dmitry Samersoff]

Sergey,

Looks good for me.

-Dmitry


On 2014-09-12 12:46, Sergey Gabdurakhmanov wrote:
> Dmitry,
> 
> New patch:
> http://cr.openjdk.java.net/~sgabdura/8057564/webrev.01/
> 
> 
> My answers:
> 
> 1. You should not free lpSecurityDescriptor if it's null (ll.291)
> 
> I checked MSDN
> http://msdn.microsoft.com/en-us/library/windows/desktop/aa366730%28v=vs.85%29.aspx
> "If the /hMem/ parameter is *NULL*, *LocalFree* ignores the parameter
> and returns *NULL*."
> 
> 2. It's better to re-arrange code a bit:
> 
> if InitializeSecurityDescriptor or SetSecurityDescriptorDacl fails,
> free lpSecurityDescriptor immediately and continue with
> lpSecurityDescriptor == NULL
> 
> Done.
> 
> 
> 3. Make sure it works on all supported platforms: this code rise minimal
> server version to windows 2003 server.
> 
> In Windows 2003 server my fix will create a new security attributes.
> If SetSecurityDescriptorDacl or InitializeSecurityDescriptor will return
> false on Windows XP
> then my patch will pass NULL to CreateNamedPipe and the code will use
> default security descriptor.
> 
> 
> BR,
> Sergey
> 
> On 11.09.2014 16:16, Dmitry Samersoff wrote:
>> Sergey,
>>
>> 1. You should not free lpSecurityDescriptor if it's null (ll.291)
>>
>> 2. It's better to re-arrange code a bit:
>>
>> if InitializeSecurityDescriptor or SetSecurityDescriptorDacl fails,
>> free lpSecurityDescriptor immediately and continue with
>> lpSecurityDescriptor == NULL
>>
>>
>> 3. Make sure it works on all supported platforms: this code rise minimal
>> server version to windows 2003 server.
>>
>> -Dmitry
>>
>>
>>
>> On 2014-09-11 15:49, Sergey Gabdurakhmanov wrote:
>>> Hi,
>>>
>>> Could I please have a review of this small fix.
>>>
>>> webrev: http://cr.openjdk.java.net/~sgabdura/8057564/webrev.00/
>>> bug: https://jbs.oracle.com/bugs/browse/JDK-8057564
>>>
>>> Problem description:
>>> On Windows 7 with User Account Control (UAC) enabled, JVM hangs at
>>> getAgentProperties or getSystemProperties after attaching from a "high"
>>> IntegrityLevel JVM to a "medium" IntegrityLevel JVM, using Attach API:
>>> attachedVM = com.sun.tools.attach.VirtualMachine.attach(pid);
>>> final Properties systemProperties = attachedVM.getSystemProperties();
>>>
>>> Root cause:
>>> In WindowsVirtualMachine.attach  is implemented with named pipes.
>>> If named pipe was created with default security properties then windows
>>> will not allow process with"medium" IntegrityLevel  to be attached to a
>>> processwith "high" IntegrityLevel.
>>>
>>> Solution:
>>> Create security properties that allow requested connection.
>>>
>>> I'm going to push this fix into JDK9, 8 and 7.
>>>   BR,
>>> Sergey
>>>
>>
> 


-- 
Dmitry Samersoff
Oracle Java development team, Saint Petersburg, Russia
* I would love to change the world, but they won't give me the sources.