Opened 7 years ago

Closed 7 years ago

#695 closed Bug / Defect (notabug)

Nonpaged pool leaks memory whenever OpenVPN is running

Reported by: Kryo Owned by:
Priority: major Milestone:
Component: Generic / unclassified Version: OpenVPN 2.3.11 (Community Ed)
Severity: Not set (select this one, unless your'e a OpenVPN developer) Keywords:
Cc: Samuli Seppänen


I'm running OpenVPN 2.3.11 on Windows 8.1. I have uninstalled OpenVPN and tap and reinstalled them and the issue persists.

I've recently discovered that my nonpaged pool slowly grows in size (verified with RamMap? and shows in task manager) and eventually takes up all memory, slowing the computer to a crawl. I've used RamMap? to monitor when this growth happens, and it's only when openVPN is running and network is being used. This issue could have been happening for a lot longer than I have noticed, since it obviously goes away at reboot and only becomes detrimental to performance when the computer has been on for extended periods of time.

I tried to diagnose the cause with xperf, and all captures done while openVPN is running show a growing nonpaged pool, whereas captures taken while OpenVPN is not running show a perfectly normal flat graph.

The leaking memory is under pooltag "NDnd", associated with Ndis.sys, and xperf lists ntdll.dll > msvcr110.dll > tcpip.sys > ndis.sys as hogging all the memory.

As nonpaged pool leaking is usually associated with driver issues, could OpenVPN and/or TAP be causing this, as the issue manifests only when traffic is going through OpenVPN.

The only other programs I can think of that could be interfering with the network drivers are Avast Antivirus and Comodo Firewall, do they have any known conflicts?

Change History (4)

comment:1 Changed 7 years ago by Gert Döring

Cc: Samuli Seppänen added

Which tap driver is this? tap-windows (I00x installers) or tap-windows6 (I60x installers)?

It could well be the tap driver, *or* avast / comodo - so you might want to test with either and both turned off. "Security suites" are known to cause the most weird issues on windows.

comment:2 Changed 7 years ago by Kryo

Sorry for late reply, the ticket system kept throwing errors and I gave up. I'm chiming back in to say that it's okay to close this one, it's resolved now. Avast seemingly had a big update a few days ago, and I haven't had a single megabyte leak ever since. I can't obviously be 100% sure what was causing it, but since even I can't reproduce it anymore, I guess this ticket is redundant now.

comment:3 Changed 7 years ago by Samuli Seppänen

Hi Kryo,

I noticed that your earlier replies were tagged as spam, which is why they did not get through. We had a massive (human) spammer attack a while back, and the various spam filters we setup after that seemed to disagree which commits are ham and which are spam. Sorry for the inconvenience, and thanks for the information!

I'll close this ticket as "not a bug" - please reopen as necessary.

comment:4 Changed 7 years ago by Samuli Seppänen

Resolution: notabug
Status: newclosed
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