Linked by snydeq on Wed 5th Aug 2009 19:11 UTC
Windows Windows 7 RTM Build 7600.16385 includes a potentially fatal bug that, once triggered, could bring down the entire OS in a matter of seconds: "The bug in question - a massive memory leak involving the chkdsk.exe utility - appears when you attempt to run the program against a secondary (i.e. not the boot partition) hard disk using the "/r" (read and verify all file data) parameter. The problem affects both 32-bit and 64-bit versions of Windows 7 and is classified as a 'showstopper' in that it can cause the OS to crash (Blue Screen of Death) as it runs out of physical memory," reports InfoWorld's Randall Kennedy. Microsoft is claiming the bug is a chipset driver issue, but Kennedy's testing of the latest Intel INF Update Utility driver set and VMware virtualized chipset drivers suggests otherwise. "This is clearly a Microsoft bug - and the fact that it manifests itself via the chkdsk.exe utility makes me wonder if it isn't something intrinsic to the Windows 7 version of the New Technology File System (NTFS) driver stack." Worse still, user comments suggest that Windows Server 2008 R2 suffers from the same flaw.
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Show stopper yes...
by Tuishimi on Wed 5th Aug 2009 19:29 UTC
Tuishimi
Member since:
2005-07-06

...but it should literally take the engineers one day to find and fix the bug. It's probably something relatively simple, possibly an optimization that they did not think through.

I say this having had experience maintaining operating system and file system utilities for a major OS/company.

LOL! Now I feel like I can't post sentences like the previous one because of the "10 most annoying" thread.

Reply Score: 2

RE: Show stopper yes...
by satan666 on Wed 5th Aug 2009 20:42 UTC in reply to "Show stopper yes..."
satan666 Member since:
2008-04-18

...but it should literally take the engineers one day to find and fix the bug. It's probably something relatively simple, possibly an optimization that they did not think through.


Maybe, but quick, untested fixes tend to require more fixes later.

Reply Score: 4

RE[2]: Show stopper yes...
by Tuishimi on Wed 5th Aug 2009 20:50 UTC in reply to "RE: Show stopper yes..."
Tuishimi Member since:
2005-07-06

There is that... sometimes.

Reply Score: 2

RE[3]: Show stopper yes...
by Delgarde on Wed 5th Aug 2009 21:49 UTC in reply to "RE[2]: Show stopper yes..."
Delgarde Member since:
2008-08-19

There is that... sometimes.


Only "sometimes"? In my experience, a quick fix made under time pressure will almost inevitably introduce at least one new bug...

Reply Score: 2

RE[4]: Show stopper yes...
by Tuishimi on Wed 5th Aug 2009 22:23 UTC in reply to "RE[3]: Show stopper yes..."
Tuishimi Member since:
2005-07-06

In my experience sometimes the problem was so simple that it is obvious, and requires only a quick and small code change.

Reply Score: 2

RE[4]: Show stopper yes...
by Tuishimi on Wed 5th Aug 2009 22:26 UTC in reply to "RE[3]: Show stopper yes..."
Tuishimi Member since:
2005-07-06

Allow me to elaborate... two "showstopper" bugs I have fixed that caused OS crashes where simple initialization issues. Shared memory variables were initialized, then cleared (accidentally) but another section of code, then referenced.

In these two cases it literally came down to moving two lines of code and documenting that certain things need to happen in a certain order.

Reply Score: 2

RE[5]: Show stopper yes...
by Tuishimi on Wed 5th Aug 2009 22:26 UTC in reply to "RE[4]: Show stopper yes..."
Tuishimi Member since:
2005-07-06

...admittedly it was because of a rarely taken path in the code... but you get the point.

Reply Score: 2

It's a driver bug!
by Karitku on Wed 5th Aug 2009 19:58 UTC
Karitku
Member since:
2006-01-12

Microsoft (VP Sinofsky) already said it's bug in chipset drivers that Microsoft provides in Windows 7 and in Windows 2008 R2 because they both use same driver. Most likely it's generic driver for large amount of HW.

Reply Score: 1

RE: It's a driver bug!
by Lennie on Wed 5th Aug 2009 23:42 UTC in reply to "It's a driver bug!"
Lennie Member since:
2007-09-22

I doubt it's a driver bug if in the summary it says people have been able to repeat it with running as a virtual-machine, which I doubt uses the same driver.

Reply Score: 1

RE[2]: It's a driver bug!
by f0dder on Thu 6th Aug 2009 00:35 UTC in reply to "RE: It's a driver bug!"
f0dder Member since:
2009-08-05

Could be a bug in the NTFS stack rather than a chipset driver - the NTFS drivers don't change depending on hardware.

Reply Score: 1

RE[2]: It's a driver bug!
by Karitku on Thu 6th Aug 2009 06:52 UTC in reply to "RE: It's a driver bug!"
Karitku Member since:
2006-01-12

I doubt it's a driver bug if in the summary it says people have been able to repeat it with running as a virtual-machine, which I doubt uses the same driver.

How does this rule out driver bug? You are aware that VMs lie guest OS what driver to use, most likely it is some generic all purpose driver. Again my point is based on 2 facts: 1) Few people confirmed that using chipset drivers from manufacturers fix this (Hotfix forum user), 2) Bug doesn't happen on every machine.

Reply Score: 1

Windows Update
by sukru on Wed 5th Aug 2009 22:19 UTC
sukru
Member since:
2006-11-19

They will have enough time to post an update. No worries here.

Reply Score: 3

not a new bug
by f0dder on Thu 6th Aug 2009 00:33 UTC
f0dder
Member since:
2009-08-05

I ran into the problem on 64bit build 7127. Dunno if URLs are allowed on first post; there's a DonationCoder thread on "Windows 7 evaluation" where I briefly mention the issue May 31st.

BSOD confirmed after running out of physical memory (no pagefile). Although the memory growth is visible in chkdsk.exe, I'd guess there's some other factors involved as well - I've never seen a usermode memory exhaustion cause BSOD before.

Should mention that this is a vLited Win7 install, and that I do run intel chipset drivers.

Edited 2009-08-06 00:34 UTC

Reply Score: 1

Sensationalism, meet perspective
by malxau on Thu 6th Aug 2009 00:35 UTC
malxau
Member since:
2005-12-04

Disclaimer: I work for Microsoft, and I work on NTFS.

Chkdsk intentionally uses lots of RAM to cache information in order to make the process complete as quickly as possible. The fact that this is using RAM is not, in itself, a problem.

The original report was of a bugcheck during this process. That really would be a problem. The original reporter upgraded drivers and no longer saw the bugcheck.

We have, in the last 30 or so hours, run chkdsk on hundreds of machines to see if we can find the cause of the crash. As of this writing, we have been unable to reproduce the crash condition; and since the original reporter can no longer generate the crash, we are left with one crash on one machine that no longer occurs. We have not been able to examine what caused any machine to crash in this process.

At this point, there's nothing to indicate that it's a bug users will frequently encounter, that it's a showstopper, or anything else.

There is a good chance that the original issue occurred presicely because the disk device was making mistakes (why does one run 'chkdsk /r'?)

A better blog post describing this bug can be found at http://blogs.zdnet.com/Bott/?p=1235 . See also Steven Sinofsky's response to the original reporter at http://www.chris123nt.com/2009/08/03/critical-bug-in-windows-7-rtm#... .

If anyone out there is encountering crashes when running chkdsk, please let me know. I'll make sure it gets investigated promptly.

Since I'm a regular OSNews reader, when there is a nasty bug in the "NTFS driver stack", OSnews readers will be amongst the first to know. For better or worse (depending on your intentions) today is not that day.

Reply Score: 9

f0dder Member since:
2009-08-05

I've just ran chkdsk on my system, but terminated when I hit 7GB commit, with chkdsk consuming 5.3GB - didn't feel like going higher and risking a BSOD right now.

EDIT: happens on both my 140gig windows-stripe and my 36gig regular partition that's on the same disk as the system partition.

Edited 2009-08-06 00:45 UTC

Reply Score: 2

malxau Member since:
2005-12-04

Again, high memory usage is expected. The BSOD is what's interesting. On my machine (which has 8Gb RAM) I saw chkdsk get to ~6.5Gb working set, but it still completed without problems.

Reply Score: 1

f0dder Member since:
2009-08-05

Such high memory usage sounds very wrong to me, though - I can see the point in caching data structures during the FS integrity checks to speed up things, but why (try to) cache all the data sectors? Isn't the logic of the surface scan to attempt-read, mark-bad + relocate on error?

BSOD or not, there's definitely something to fix ;)

Reply Score: 1

f0dder Member since:
2009-08-05

OK, haven't been able to reproduce BSOD - so that has probably been fixed by driver/whatever update. Which is good, I guess.

I still find it problematic memory usage goes through the roof, I have no chance to complete a surface scan since physical memory gets exhausted.

Reply Score: 1

Phloptical Member since:
2006-10-10

I've run chkdsk on a few hard drives mounted through a USB converter during my time with Win 7 RC and haven't come across anything like that.

Of course, that was with RC, not RTM. Still, I'm not sure this is bad enough to put the brakes on the release timeline.

Reply Score: 2

darknexus Member since:
2008-07-15

If this is triggered by a chipset driver, as Microsoft claims, then your USB drives are not likely to exhibit this behavior at all as they do not pass through the hard drive controller chipset (IDE or SATA) on your motherboard. It depends on which "chipset" they are referring to however and also depends on which particular driver is affected.

Reply Score: 2

Overstated?
by drstorm on Thu 6th Aug 2009 01:58 UTC
drstorm
Member since:
2009-04-24

Critical Bug Could Derail Windows 7 Launch

Quite mouthful isn't it?

Even if it is in fact a bug in chkdsk, don't you think a simple update would fix it?

Reply Score: 1

RE: Overstated?
by Adam S on Sat 8th Aug 2009 15:40 UTC in reply to "Overstated?"
Adam S Member since:
2005-04-01

That's exactly what I was thinking. In fact, the update process prompts you to do updates as the last step!

Reply Score: 1

Attention whoring much?
by Soulbender on Thu 6th Aug 2009 07:03 UTC
Soulbender
Member since:
2005-08-18

A bug in an obscure feature that most users don't even know about and even fewer use is show stopper?

Reply Score: 1

RE: Attention whoring much?
by darknexus on Thu 6th Aug 2009 17:16 UTC in reply to "Attention whoring much?"
darknexus Member since:
2008-07-15

I agree, all the while they're leaving open a massive security hole? I'd think chkdsk would be low priority by comparison.

Reply Score: 2

PlatformAgnostic Member since:
2006-01-02

Typical Randall C. Kennedy.

Reply Score: 2