WMI query with multiple sets causes stack overflow

[cmd]

Hello again Glenn!

I’ve managed to work myself into a hole again. I’m attempting to use WMI queries to gather information and store it in variables via the set: functionality. It seems that specifying a single variable via the WMI %name% return style doesn’t set the value, and instead only puts the literal string %WhateverProperty% into the variable.

The big one though I ran into when attempting to collect multiple pieces of information in a single query. Specifying more than one variable in the set: section causes a stack overflow during UpdateEntries (according to the log). DesktopInfo.exe then closes (and will leave DesktopInfo64.exe orphaned if it was running.

Windows version: Windows 10 Pro for Workstations 20H2 (19042.804)
Product version: 2.10.1.3742
Expected output: Result: MYMACHINE\myUserName WORKGROUP PC-Model
Actual output: Result: %UserName% %Workgroup% %Model% (Or a stack overflow with no output.)

Small ini to reproduce issue: (uncomment one of the WMI lines at a time. I left the stack overflow line in.)

[options] log=desktopinfo.log log-level=debug desktopinfo64=1 inimonitortime=2 [items] # Display DTI version as a sanity check. FILE=active:1,interval:0,color:%Highlight%,type:version,text:DTI Version,file:DesktopInfo.exe,display:%2 # Uncomment one of the WMI lines below. # Works, shows expected values: #WMI=hidden:0,interval:0,namespace:root\cimv2,query:Win32_ComputerSystem,display:%UserName% %Workgroup% %Model% # Sets %FullUser% to the literal string "%UserName%", but also does not cause crash: #WMI=hidden:1,interval:0,namespace:root\cimv2,query:Win32_ComputerSystem,set:FullUser=%UserName% # Causes Stack Overflow on UpdateEntries: WMI=hidden:1,interval:0,namespace:root\cimv2,query:Win32_ComputerSystem,set:FullUser=%UserName% Workgroup=%Workgroup% Model=%Model% # Output COMMENT=text:Result: %FullUser% %Workgroup% %Model%

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[options] log=desktopinfo.log log-level=debug desktopinfo64=1 inimonitortime=2   [items] # Display DTI version as a sanity check. FILE=active:1,interval:0,color:%Highlight%,type:version,text:DTI Version,file:DesktopInfo.exe,display:%2   # Uncomment one of the WMI lines below.   # Works, shows expected values: #WMI=hidden:0,interval:0,namespace:root\cimv2,query:Win32_ComputerSystem,display:%UserName% %Workgroup% %Model%   # Sets %FullUser% to the literal string "%UserName%", but also does not cause crash: #WMI=hidden:1,interval:0,namespace:root\cimv2,query:Win32_ComputerSystem,set:FullUser=%UserName%   # Causes Stack Overflow on UpdateEntries: WMI=hidden:1,interval:0,namespace:root\cimv2,query:Win32_ComputerSystem,set:FullUser=%UserName% Workgroup=%Workgroup% Model=%Model%   # Output COMMENT=text:Result: %FullUser% %Workgroup% %Model%

Log output from stack overflow:

25-02-21 11:29:33:755 DEBUG UpdateEntries Complete. 25-02-21 11:29:33:756 DEBUG GetFileWatch: DesktopInfo.exe 1 25-02-21 11:29:33:757 DEBUG FILE run, time: 0ms 25-02-21 11:29:33:758 DEBUG FILE process 25-02-21 11:29:33:759 DATA FILE 2.10.1.3742 25-02-21 11:29:33:761 DATA FILE () True 25-02-21 11:29:33:762 DEBUG WMI: Namespace=root\cimv2 Query=Win32_ComputerSystem 25-02-21 11:29:33:778 DEBUG WMI run, time: 16ms 25-02-21 11:29:33:779 DEBUG WMI process 25-02-21 11:29:33:780 DATA WMI %rowcount% 25-02-21 11:29:33:782 DATA WMI () True 25-02-21 11:29:34:658 ERROR UpdateEntries: Stack overflow

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25-02-21 11:29:33:755 DEBUG UpdateEntries Complete. 25-02-21 11:29:33:756 DEBUG GetFileWatch: DesktopInfo.exe 1 25-02-21 11:29:33:757 DEBUG FILE run, time: 0ms 25-02-21 11:29:33:758 DEBUG FILE process 25-02-21 11:29:33:759 DATA  FILE 2.10.1.3742 25-02-21 11:29:33:761 DATA  FILE () True 25-02-21 11:29:33:762 DEBUG WMI: Namespace=root\cimv2 Query=Win32_ComputerSystem 25-02-21 11:29:33:778 DEBUG WMI run, time: 16ms 25-02-21 11:29:33:779 DEBUG WMI process 25-02-21 11:29:33:780 DATA  WMI %rowcount% 25-02-21 11:29:33:782 DATA  WMI () True 25-02-21 11:29:34:658 ERROR UpdateEntries: Stack overflow

[rtruss]

I was able to get this to work, i am not in a workgroup but it still worked with domain in its place

WMI=hidden:0,interval:0,namespace:root\cimv2,query:Win32_ComputerSystem,Row-text:FullUser| DOMAIN| Model,display:%UserName%| %DOMAIN%| %Model%

Workgroup and Model are already ‘known’ to dti i believe so a set would not be needed for those.

hope that helps.

[cmd]

Hey rtruss, I appreciate that workaround. I was more demonstrating the stack overflow, as it seems to happen with any time I use multiple sets from a WMI query.

I did manage to work around it for my use case too: if I break each WMI query set into a single set per query, using display and a single, non-‘equals’ set like so:

WMI=hidden:1,interval:0,namespace:root\cimv2,query:Win32_ComputerSystem,set:FullUser,display:%UserName%

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WMI=hidden:1,interval:0,namespace:root\cimv2,query:Win32_ComputerSystem,set:FullUser,display:%UserName%

Everything works like I’d expect!

Obviously there’s un-needed overhead in running the query multiple times, but the majority of the data I’m collecting I’m doing with interval:0, so it’s a relatively small issue for now!

[webmaster]

I’ve fixed the multi SET for WMI items. I couldn’t reproduce the stack overflow though. It’s possible I fixed it while working on other things.

[cmd]

Awesome news, Glenn!

I’ll keep my eye open for the next release and will see if I can reproduce it at all and let you know if it got fixed along the way!

Cheers

[webmaster]

I just loaded up 2.10.1 and reproduced your error so I can say the bug has been fixed in the next release.

[cmd]

Incredible! I wish everything had the same sort of turnaround you do, Glenn. Thanks a heap!

[webmaster]

Having said that, I notice it’s been 2 months since the last release which is unusual. I like to do updates monthly. But I have a good excuse (I think), I’ve been experimenting with a plugin system.

[Author]

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