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The Story Behind a Windows Security Patch Recall 135

Posted by CowboyNeal
from the trial-and-human-error dept.
bheer writes "Raymond Chen's blog has always been popular with Win32 developers and those interested in the odd bits of history that contribute to Windows' quirks. In a recent post, he talks about how an error he committed led to the recall of a Windows security patch."
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The Story Behind a Windows Security Patch Recall

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  • What the... (Score:2, Insightful)

    by P2PDaemon (723609)
    Why are the trolls out in force here? Oh, Microsoft... Nevermind...
  • by Jadware (1081293) on Friday May 04, 2007 @04:53PM (#18994781)
    Raymond Chen would be iFired, or at least told to iRTFM.
  • The Money Quote (Score:4, Interesting)

    by SixFactor (1052912) on Friday May 04, 2007 @04:55PM (#18994821) Journal

    You're about to be Slashdotted.

    Seriously, it's good to get a glimpse of the interactions in the dev side of MS. It's astonishing that MS even allows this to happen at all. The March 07 Wired had a feature on Channel 9 [wired.com] that humanized the MS organization quite a bit, IMO. It's not just about chair-throwing, marketing hyperbole, and world domination after all... oh wait.
    • Re: (Score:3, Funny)

      by snowgirl (978879)
      Your sig: Sheep, Sheepdog, or Wolf: Choose.

      I choose moof [wikipedia.org]!
      • Re: (Score:1, Offtopic)

        by SixFactor (1052912)
        That's funny. The origin of my sig, if you didn't know already can be found here [blackwaterusa.com]. It presents an apt analogy of human reactions to danger (wolves).
  • Fascinating (Score:5, Insightful)

    by wbean (222522) on Friday May 04, 2007 @05:00PM (#18994909)
    This is fascinating. The system for exiting a process is so complicated that a lot of implementations fail. In fact, it's so complicated that even Microsoft can't get it right. Sounds like an unbounded loop to me.
    • Re: (Score:2, Insightful)

      by Anonymous Coward

      Sounds like an unbounded loop to me.

      That's quite an appropriate analogy. If you RTFA, you would know that the loop in question is designed to be bounded by a guard variable/event, but they had already terminated the thread that sets the guard to the state that allows the loop to terminate.

      The root cause of the hang is that most programmers are not really aware of the states involved at process termination, so they assume invalid things about the DLL process termination event -- namely that it's okay to wai

    • Re:Fascinating (Score:5, Interesting)

      by Timesprout (579035) on Friday May 04, 2007 @05:50PM (#18995655)
      Raymond has touched on the complexity of their software before and noted that oftentimes the complexity was not acually a product of the fuctionality but due to fixes, patches and additions to the code over time. To his credit he has in the past admitted that issues similar to this one were introduced because the core problem ie loading faulty shell extensions was not addressed directly for reasons of time/money/too scared to touch it/whatever and the hacks and workarounds only served to pointlessly bloat the complexity of the whole system. It's also worth noting that this complexity creep was not entirely due to MS. They had 10s of millions users with god knows how many applications which the MS dev teams struggled to support with backwards compatability etc. Raymond has admitted in the past that specific checks were put in the OS for certain applications to keep them functioning. Nice if you are a third party developer but just asking for trouble for your OS.
      • Revealing (Score:1, Interesting)

        by Anonymous Coward
        And points out how their anti-competitive lockin approach has not only bitten them in the ass repeatedly, but only gotten worse as they incur additional scars on the scar tissue. The only reason they have to have their developers struggling to support third party apps is because they have never released proper APIs, and do not follow their own published interface methods when implementing features in Windows. With publicly available, stable APIs and consistent implementation the third party developers cou
      • Its only useful in a closed-source world where you cannot modify programs to suit the new API's.

        It accumulates complexity over time.

        The result is that even Microsoft can't get reasonably trivial things right.
        Not to mention almost all Windows software code being highly complicated compared to equivalent code on other systems.
        • Re: (Score:3, Insightful)

          Its only useful in a closed-source world where you cannot modify programs to suit the new API's.

          How much open source work have you actually done? I've done a lot, and this idea is one I see very often in people who haven't done any serious API development work before. The approach of attempting to patch every app when an API changes simply doesn't scale. There's a reason all the important open source APIs (gtk, glibc, alsa, X etc) have "gone stable" in the past 5 years, and it's simply a better approach.

          • Re: (Score:3, Interesting)

            by Peaker (72084)

            There's a reason all the important open source APIs (gtk, glibc, alsa, X etc) have "gone stable" in the past 5 years, and it's simply a better approach.

            But they only have to maintain source-level compatibility. Microsoft has to maintain binary-level compatibility.

            Also, when specific things are extremely and seriously broken, compatibility can be dropped altogether, and some buggy programs broken. Microsoft cannot afford to break buggy programs, even if those are few and far between - nobody can fix them.

            M

            • Re: (Score:2, Insightful)

              by Bill Dog (726542)
              Using a multi-threaded approach here, when SMP scalability is not an issue, suggests that either their API design is crap, and requires threading, or that their engineers are incompetent and use threads unnecessarily. Threads are never trivial - but what they were trying to do was quite trivial. Its their fault they involved threads in there.

              This is one of the stupidest comments I've read here in a long time. A secondary "watchdog" thread was employed to enforce a time-out on the helper program's sniffing o
              • by Peaker (72084)

                If you knew anything about what you're trying to talk about, you'd know that multi-threading is used for these kinds of situations, as well as in GUI programming. And not just "when SMP scalability is an issue". This has nothing to so with the Win32 API design, it just was tackling a very specific problem. It doesn't mean that the Win32 API "requires threading", or that MS's engineers are incompetent, and that they used an additional thread unnecessarily here. Threads can be trivial, and this is I would say

                • by Bill Dog (726542)
                  Threading is used in GUI's so that redraws and responding to the user can still take place while it's processing the user's last command or commands. This is how "incompetent engineers" for the Win32 and Java platforms do it, at least. What pray tell are the "far simpler approaches"?

                  And how do you write a program that hosts plug-in executable code, to check whether it will hang its host, without the "unnecessary complication" of another thread of execution, either in the program itself, or in another proces
                  • Re: (Score:3, Interesting)

                    by Peaker (72084)

                    Threading is used in GUI's so that redraws and responding to the user can still take place while it's processing the user's last command or commands. This is how "incompetent engineers" for the Win32 and Java platforms do it, at least. What pray tell are the "far simpler approaches"?

                    The far-simpler approach is to use asynchronous programming. Never use blocking API calls. All good API's always provide non-blocking interfaces.
                    If long computations are required, split them up into short computations and run th

    • Re: (Score:3, Interesting)

      by Quantam (870027)
      You should read The Old New Thing site (or the book by the same name, which is basically just a cleaned up and edited version of everything on the site). For those not familiar with him, Raymond Chen is THE backward compatibility guy at MS. He and his minions have to find all the badly programmed programs that break when Windows improvements are ready to ship (for examples of just how bad some of these programs are, read the site; little things like walking the stack from a window callback function to find
      • Raymond Chen is also a condescending tool. (Check out Verity Stob's recent article [regdeveloper.co.uk] for a good laugh at his expense, or this [joelonsoftware.com] Joel on Software forumn thread.)
        • by Quantam (870027)
          Dear Gord no. It was bad enough with Linus and RMS. The world does NOT need another person that makes headlines every time he says something.
    • Re: (Score:3, Interesting)

      by Chops (168851)
      It's not just that -- there's a whole little gang of design flaws responsible here, each of them egging the others on like adolescent boys with dangerous tools at their disposal. To all of the people saying, "well, it has to be that way because Microsoft has 5 billion trillion gazillion apps to support and they're not responsible for third party blah blah blah," I say this: No. Shut up. Linux vendors release updates for a body of software that is a massive superset of what Windows Update covers, often w
  • by drinkypoo (153816) <martin.espinoza@gmail.com> on Friday May 04, 2007 @05:02PM (#18994935) Homepage Journal

    he talks about how an error he committed led to the recall of a Windows security patch.

    Okay, he made an error. Why the HELL wasn't it caught in QA? Microsoft wants us to believe that the reason that we have to wait for patches is that they are getting some kind of exhaustive QA. This patch and executable were specifically created to avoid problems with invalid shell extensions. Don't you think that given that fact the thing to do would be to test it with some invalid shell extensions?

    This is the reason that Windows admins have to be so much more paranoid about patches than the rest of us. A Windows patch is highly likely to be a big pile of crap that causes your system to not work properly. I think we can all remember certain service packs that broke various versions of Windows NT pretty much completely...

    If you can't have confidence that security patches will fix more than they break, how can you have sufficient confidence to even install that vendor's products, let alone count on them for mission-critical applications?

    • by jddj (1085169)

      No love for Apple on this one.

      Tried to install 10.2.8, 10.3.9, 10.4.9, or virtually any Security Update?

      C'mon, admit it: you held your breath, didn't you?

      • by drinkypoo (153816)
        Well, I have no love for Apple either (I remember System 7, and frankly I'm not all that impressed by OSX in ANY way, including look-and-smell) but I've been using OSX off and on since 10.1 and have never had the kind of problems with any OSX update that I did with whatever Win2k update that was. SP1 maybe? I blocked it out it was so bad. I just went from the latest version of OSX 10.3 to 10.4.9 (we made the update late) and the system works WAY WAY WAY better than it did before the update.
        • by dedazo (737510)

          have never had the kind of problems with any OSX update that I did with whatever Win2k update that was.

          Absolute control of the hardware on which your software runs can come in handy, I guess.

      • by mosch (204)
        C'mon, admit it: you held your breath, didn't you?

        No, I just watched them install. OS X isn't some bug-free panacea (I've had grey screens, etc.) but I've never had an update blow up my computer.
        • by bmajik (96670)
          Oh.

          http://blogs.msdn.com/mattev/archive/2004/06/21/16 1770.aspx [msdn.com]

          You should read this, which I wrote a few years ago, and which upset many mac zealots (as seen from the comments)
          • Re: (Score:3, Funny)

            by Lars T. (470328)
            Yeah, trying to fix a broken registry is SOOO much easier.
          • The fact you posted that on msdn.com AND things like that arent common at all on Mac OS means your just trolling.

            Also keep in mind that if Windows had the same symptoms then the box would just get a reinstall.
          • Re: (Score:3, Insightful)

            by mosch (204)
            So, somebody installed 10.3 on what was either the oldest possible supported laptop, or possibly an unsupported laptop, then a video driver update caused some problems, all of which were fixable by somebody who fully admitted that they don't know OS X, only Unix and Windows.

            Obnoxious, sure, but not really different than any other OS. (In fact I have had brand-spanking new Windows hardware that would lose video if I applied WindowsUpdate recommended driver updates.)

            I'd have to be pretty stupid to think that
    • by NickFitz (5849) <slashdot AT nickfitz DOT co DOT uk> on Friday May 04, 2007 @05:16PM (#18995169) Homepage

      As he points out in his response to the second comment on his blog post, internal testing can't possible cover every single third party shell extension on the planet. (Nor does he try to use that as an excuse for his screw-up.)

      • by geekoid (135745) <dadinportland.yahoo@com> on Friday May 04, 2007 @05:28PM (#18995323) Homepage Journal
        While Kudos to him for taking responsibility, the QA excuse doesn't seem to fit.

        IT was an error hat happened all the time, under its most basic use.

        While the global OS QA might be excused for some wierd bug that happens under unforseen circumstance, this wasn't even tested to see if it fixed what it wqas supposed to.

        Sounds like sloppy(i.e. none) QA to me.
        • by geekoid (135745)
          "Sounds like sloppy(i.e. none) QA to me."

          Much like the QA that went into the spelling of my post.
        • by SEMW (967629)
          Huh? Were you reading a different post to me? The patch worked fine except if a 5600 series HP printer driver (if one of the comments lower down was correct) is installed.
        • No, you didn't understand the explanation. This sort of understanding failure is exactly what caused the need for the verclsid program in the first place!

          The problem was that this specific shell extension (for an obsolete HP printer) contained a concurrency bug - it tried to synchronize with a thread in its DLL detach function. This is never correct, because in a DLL detach you can't make any assumptions about the liveness of other threads. Because there are buggy shell extensions out there that hang, the

      • by drinkypoo (153816)

        internal testing can't possible cover every single third party shell extension on the planet.

        Especially if they aren't actually trying to break it!

        If they were trying to break it, then they almost certainly would have discovered this flaw.

        Most likely they just have a small handful of shell extensions that they would install and test with.

        What this says to me is that there was no intelligence behind the test plan.

        Sure, the guy made a mistake. But it is the purpose of testing to make sure that the softwa

        • by Quantam (870027)
          Most likely they just have a small handful of shell extensions that they would install and test with.

          I see even after people responded to you you STILL didn't RTFA. The particular shell extension was for a printer that was so old it wasn't produced at the time the patch was made. How many pieces of hardware does Windows support? Do you want them to test EVERY one of them with every single bug fix? You're batshit insane; even the entire OSS community combined couldn't pull that off.
          • by mangu (126918)
            How many pieces of hardware does Windows support? Do you want them to test EVERY one of them with every single bug fix?


            The way I envision Microsot QA is a huge warehouse full of every hardware device they could get, with computers having every version of OS that they ever shipped and a switching system to let any of that hardware be tested with any of the computers. Total cost of that warehouse would be in the million$, which means about 0.1% of total Microsoft market capitalization.

            • by Quantam (870027)
              The way I envision Microsot QA is a huge warehouse full of every hardware device they could get, with computers having every version of OS that they ever shipped and a switching system to let any of that hardware be tested with any of the computers. Total cost of that warehouse would be in the million$, which means about 0.1% of total Microsoft market capitalization.

              A million monkeys on a million computers in a big warehouse, eh? Heh, now there's a mental image. I wonder how long it would take them to do
            • by Blakey Rat (99501) on Friday May 04, 2007 @07:46PM (#18997015)
              And the manpower to run it all costs... how much?

              Seriously, though, just putting all that equipment in one building would create a zeppelin-hangar-sized building. Finding any specific router or PCI modem would be near impossible. The logistical difficulties of your plan I think would be insurmountable, not even considering the manpower question.

              The real point Raymond mentions is that if MS does tons of testing on all the hardware they have available, they get bad press for being slow to release patches. If not, they get bad press for having to recall buggy patches. It's a lose/lose situation for them.
      • by Nutria (679911)
        As he points out in his response to the second comment on his blog post, internal testing can't possible cover every single third party shell extension on the planet.

        But it shouldn't have such a fragile design in the first place.

        Of course, a lot of things about MSFT operating systems should be different, but aren't.

    • by BAILOPAN (694545)
      If you read the article, you'd see he addresses that sort of comment. There's two issues:

      1) There's a lot of pressure to get a security patch out as soon as possible;
      2) It's impossible to test every single case (the breaking case was a shell extension for a printer that wasn't even being manufactured anymore)

      As Raymond likes to say, "you can't have everything."
      • Re: (Score:1, Flamebait)

        by drinkypoo (153816)

        If you read the article, you'd see he addresses that sort of comment.

        Now look kid, I read the fucking article. Don't make stupid assumptions. It only makes YOU look like an ass. It doesn't do shit to me except piss me off and suggest to me that I'm dealing with an idiot.

        1) There's a lot of pressure to get a security patch out as soon as possible;

        Microsoft still typically makes us wait for them, days to weeks after they are reputed to be completed. One of two things is true in these situations. Either the

        • Ya know, you are right, you are an arrogant ass, or whatever you admitted to be - and pretty good at it, as you also admitted... but right as rain as well!!! :-)

          Gotta add you to my friends list - for both reasons!!! ;-)

          Oh - but here's something to add to your response... if MS knew which printer driver for which outdated printer (as they seem to be indicating they do), then why not use that driver for the test? Of course, I too agree with you and think especially with the number of responses about this

    • by Quantam (870027)
      Okay, he made an error. Why the HELL wasn't it caught in QA? Microsoft wants us to believe that the reason that we have to wait for patches is that they are getting some kind of exhaustive QA. This patch and executable were specifically created to avoid problems with invalid shell extensions. Don't you think that given that fact the thing to do would be to test it with some invalid shell extensions?

      How to tell if somebody has only read the summary: they ask a question that was explicitly answered in the
    • by Alon Tal (784059)
      Raymond answered this question in his comments section -- see http://blogs.msdn.com/oldnewthing/archive/2007/05/ 04/2402028.aspx#2412469 [msdn.com]. The bug was in a shell extension provided with a printer that was not even manufactured anymore when this patch was developed. Even exhaustive QA cannot be reasonably expected to test all Windows shell extensions in existence.
      • Raymond did not answer the question, he made a statement that may or may not be unrelated.

        "Is it raining out?"

        "Dont you see my umbrella?"

        And what does that mean? Nothing other than I brought my umbrella with me to work for reasons I havent stated... nor have I stated it was raining.

        Raymond's marketing doublespeak doesnt say much of anything other than he made a mistake (with some explanation of the mistake) and that he is upset that people complain that a patch takes too long and that people complain

    • by bmajik (96670) <matt@mattevans.org> on Friday May 04, 2007 @06:28PM (#18996087) Homepage Journal
      I'm a software tester at Microsoft, although I'm not involved with the Windows team or the security process.

      Just so we're clear:

      Microsoft is not selling you products that have gone through exhaustive QA, nor are we issuing patches that have gone through exhaustive QA.

      The key word here is "exhaustive".

      You can imagine that as much as it costs a business when they get a hotfix from us that breaks them, it costs us _at least_ that much in real employee hours (dollars), not to mention the direct and indirect, monetary and non-monetary costs of having to admit that we screwed up a patch.

      Software testing cannot tell you how good your product is, only in what ways it doesn't appear to be bad. Every release decision is a _decision_, and its based on necessarily incomplete data put together by imperfect humans with non-infinite time.

      A release decision is a culmination of many nested risk/reward tradeoffs. Sometimes, that decision gets made incorrectly, or at least gets made in a way with known or even unknown downsides.

      You'll notice that the patch was an interaction problem with an antique 3rd party product. From my time doing admin work on Solaris, IRIX, and Linux machines, I can tell you the big difference between this situation and "those" situations. I never _ran_ 3rd party software on Solaris, IRIX, or Linux (well, I ran 3rd party software on linux all the time, but i just expected it to break anytime i patched anything.. it was a mandatory recompile of any dependant libraries and applications).

      I also think your glasses are a little rosy. There were some IRIX patches back in the day that you couldn't back out. Or that wrecked your XFS volumes. I think in every operating system there has been at least one instance of a patch / upgrade / new version that some user opted to back out, because it hurt them and their scenarios more than it helped.

      I run very little non-Microsoft software on my windows machines and thus I rarely worry about patches from MS. If you're doing something weird, you need to be more risk averse. IIRC, Microsoft's official recommendation for businesses with critical systems is to install patches in a pre-production environment to ensure compatability with the specific intricacies of your business. You can choose to play fast and loose, but you should be aware that you're making a risk/reward tradeoff decision, based on incomplete data.

      Just like we have to do.

      • by Nutria (679911)
        Microsoft is not selling you products that have gone through exhaustive QA, nor are we issuing patches that have gone through exhaustive QA.

        Why not?

        http://finance.yahoo.com/q/bs?s=MSFT&annual [yahoo.com]
        Last year, your employer earned US$12,600,000,000 profit and has US$34,000,000,000 in cash. Certainly they could pony up for a comprehensive test suite.

        But... "you" don't have to. Why should MSFT create a decent product when sheeple, people who are managed by short-sighted idiots, and people trapped by vendor lock
        • Exhaustive QA means that you tried every possible case. Any state that the computer could possibly be in you must have tested. Any possible combination of hardware and drivers must be tested. In other words, Microsoft would have to test more combinations than will ever exist in the wild. If your system has more than 8 bytes of memory, good luck testing all possible combinations.

          So your test plan can't be "exhaustive" (he was using the definition: "treating all parts or aspects without omission"). Instead yo
      • by rhk (8020)
        Now there's conflicting information here. One poster says it was a common HP printer. You say it was an "antique 3rd party product". Now, unless microsoft makes printers now, I'm guessing you have a good chance of having 3rd party printer drivers on your machine.
        • by bmajik (96670)
          Actually, you'd be wrong -- HP dropped support for my printer in Vista (Photosmart 7150), last time I looked.

          Once upon a time, you could just shoot bits at the parallel port and printing would work. The HP 7150 "driver software" (which is 200mb, by the way), doesn't ever detect USB device insertion on vista. Why HP feels the need to have some convoluted, assinine way of doing this is beyond me, but they do.

          So no, there is no HP print driver stuff on my main vista machine at home. But it's not for want of
          • by rhk (8020)
            Except that the patch in question was for windows XP, not vista, IIRC.
          • by spongman (182339)
            don't buy HP devices. their driver support on both windows and mac is horrendous. not only do they install tons of unnecessary stuff, their drivers often circumvent the OS-provided APIs for performing common functions (again, windows and mac, both) thus breaking functionality in many apps that use those APIs, and since they do all this backdoor hacking, their drivers are invariably broken by OS upgrades, and they use this as a way to force you to buy a new device in conjunction with your OS upgrade. Lexmar
      • by grcumb (781340)

        I can tell you the big difference between this situation and "those" situations. I never _ran_ 3rd party software on Solaris, IRIX, or Linux (well, I ran 3rd party software on linux all the time, but i just expected it to break anytime i patched anything.. it was a mandatory recompile of any dependant libraries and applications).

        Could you please clarify what you mean here? You're apparently implying that Linux even has a concept of 'third party software [wikipedia.org]'. All software is third party in Linux, because ther

        • by Keeper (56691)
          Are you implying that running non-MS software on Windows is 'weird' and risky?

          No, he's implying that the more software you put on the machine, the more likely it is to find software on the machine that has shit code which happens to work more as a result of luck than deliberate effort.
    • Re: (Score:2, Interesting)

      > Okay, he made an error. Why the HELL wasn't it caught in QA? Microsoft
      > wants us to believe that the reason that we have to wait for patches
      > is that they are getting some kind of exhaustive QA.

      M$ doesn't have "QA". It has QC.

      Quality Assurance is the fence at the top of the cliff that at each stage prevents faults from arising, and thus from impacting on later stages of development.

      Quality Control is the ambulance at the bottom of the cliff that responds to the emergency call once the fault has b
  • Lesson (Score:5, Insightful)

    by Jeffrey Baker (6191) on Friday May 04, 2007 @05:09PM (#18995041)
    I think the lesson here is not that this guy should have been more careful about programming, it's that no amount of careful programming can overcome a stupid design. It's stupid that there are magical filenames in the form of UUIDs that cause Explorer to load and run arbitrary DLLs. You can't get around this stupidity with some kind of speculative watchdog thread that works with what sound to me like some seriously questionable heuristics.

    They should have simply got rid of the magic naming system in favor of something explicit, such as a Shell Extension Interface that a shell extension must fully implement.
    • by slamb (119285) *

      It's stupid that there are magical filenames in the form of UUIDs that cause Explorer to load and run arbitrary DLLs. ... They should have simply got rid of the magic naming system in favor of something explicit, such as a Shell Extension Interface that a shell extension must fully implement.

      It sounds like they tried to do that, but he said: "As we saw earlier, lots of people mess up IUnknown::QueryInterface". I'm not familiar with Windows or COM, but I take that to mean that the way they find out what in

    • by mac.man25 (988406)

      They should have simply got rid of the magic naming system in favor of something explicit, such as a Shell Extension Interface that a shell extension must fully implement.

      So you mean they should have rewritten a core OS API after it had already been gold mastered? Yes, it was a stupid design to begin with, but that doesn't mean that it's possible to rewrite something like that. This is exactly the reason that Vista is having problems with compatibility. Because core API's were rewritten.

    • Re: (Score:2, Informative)

      by biscon (942763)

      "They should have simply got rid of the magic naming system in favor of something explicit, such as a Shell Extension Interface that a shell extension must fully implement."

      Seems to me like they had, how would you implement plugins otherwise?. The problem is that if explorer loads these plugins (which do adhere to an interface) and they do something stupid, explorer will hang, since it is the host process. This is bad since explorer.exe on windows is responsible for running the shell.
      Therefore they choose to make a separate process (that vert something exe) try and load the plugin and run some tests. Questionable heuristics I agree, but giving those circumstances, I can't co

      • by Viol8 (599362)
        "Seems to me like they had, how would you implement plugins otherwise?. The problem is that if explorer loads these plugins (which do adhere to an interface) and they do something stupid, explorer will hang, since it is the host process. This is bad since explorer.exe on windows is responsible for running the shell."

        Do what most unix programs do - fork() first. So if the child process crashes the parent process happily carries on regardless. AFAIK Windows processes couldn't do fork() , perhaps this is not l
    • Re: (Score:3, Informative)

      You clearly have no clue how COM CLSIDs work, do you?
      There is no "magic naming system". Each plugin implements the shell extention interface and registers its CLSID; when explorer needs to load the plugin for a particular CLSID, it looks it up in the registry, finds the corresponding dll, loads it, and accesses the shell extension's COM interface.

      And to think that your post was modded "Insighful" rather than "Arrogantly Ignorant".
      • Re: (Score:3, Informative)

        by Jeffrey Baker (6191)
        Thanks for your feedback ... The magic filenames are of the form {1768bcfe-9acf-4af5-b857-32eb9c640c4e} and if you name a file that way on the Desktop in Windows, Explorer looks up that UUID and loads the DLL, then QI's it into existence. The "magic" part here is that I can use _any_ DLL and Explorer will still try to QI it into a shell extension, which is obviously grossly unsafe, which is why they had to work around it.
        • Erm, how does your proposal fix this? COM has a simple negotiation mechanism where Explorer can say "Do you support FOO?" and the extension can say "Yes, here you go" or "No, I don't". If you get rid of the COM indirection in favor of a simpler plugin system, you'd have to drop this negotiation mechanism or re-implement it, and that is what would be grossly unsafe.

          COM is not the problem here. The problem is buggy code. The only policy design that is worth debating here is whether it makes sense to allow 3

      • Its not magic, maybe, its a registry filename.

        Microsoft, in its stupidity and/or attempt to complicate their system so that potential compatibility is more difficult, duplicated the functionality of the "file system" with the registry. That makes registry keys such as CLSID's filenames too. The grandparent was right in calling them magic file names.
  • Honesty (Score:5, Insightful)

    by florescent_beige (608235) on Friday May 04, 2007 @06:01PM (#18995771) Journal

    This illustrates the kind of employee I like to have. One who can talk about his mistakes the same way he talks about anything else work-related.

    Some years ago I myself made a rather expensive mistake which involved the design of an aircraft structure. The fellow I was working for at the time had one of those razor-blade intellects and I got called into his office for a chat. When he asked me what happened I had two choices, weasel or turkey. In engineering it's always possible to talk the complicated talk and hope to obfusticate your way out of a situation, but fortunately I said "I make a mistake." And you know what? That was exactly the answer he was looking for.

    You see, the most important thing is not to be perfect, it's to be honest. That's what a boss, of which I am one now, wants.

    If you have a boss that doesn't want that, better watch out for yourself.

    • education (Score:2, Insightful)

      by Anonymous Coward
      Reminds me of a famous story about Jack Welch, former GE CEO. One of the company's division managers made a mistake costing the company $10 million in one quarter. When the quarterly reports came out, he got a call from headquarters telling him to be in Welch's office in NY the next morning. Welch grilled the man for some time, asking him what he was thinking and how he could possibly lose so much money. When it seemed Welch had finished, the manager said he understood that Welch had to fire him now. T
    • Re: (Score:3, Insightful)

      by labnet (457441)
      Being a Boss as well, thats exactly what our culture looks for.
      Honesty, but without emotional baggage.
      A stuffup is a stuffup, learn and move on.

      Reading /. for so many years now, you would think 90% of posters are uber humans that never make a mistake, and be dammed if you do. Not sure if I would want to work for most of the /. crowd.
       
  • by ktakki (64573) on Friday May 04, 2007 @06:22PM (#18996013) Homepage Journal
    On the day after Patch Tuesday, January 2006, I got a somewhat frantic call from a client. She's a lawyer, had a filing deadline, but could not save a document in MS Word. That's not all that this patch broke: you couldn't open My Computer or My Documents on the desktop (though you could navigate to them by typing the path in the Start -> Run box), and IE wouldn't let you type just "www.[website].com" in IE's address bar. You had to prepend the "http://".

    I verified that "Save" and "Save As..." were not working in Word. Word would just hang and only Task Mangler could shut it down. I carry the Sysinternals utilities on CD and USB key, so I rebooted and ran FILEMON, REGMON, and PROCEXP to see what was happening when I tried to save a doc in Word. Sure enough, Word would spawn verclsid.exe as a child process and then hang.

    I googled "verclsid" and "Explorer", got nothing on the web and about a dozen Usenet posts from people having the same problem. I played a hunch and renamed verclsid.exe to verclsid.exX. I do that when I'm manually hunting malware that leaves .exe and .dll files that are named just like Windows system files. Keeps my foot bullet-free.

    Problem solved. When the patch for the patch came out, a working verclsid.exe was dropped in %system% and I deleted the .exX.

    Oh, and the buggy third party shell extension came with a very common HP DeskJet printer. As for Google, the next day I googled "verclsid": there were hundreds of web results and Usenet hits. The day after, tens of thousands. This one bit a lot of people in the ass.

    k.
    • by Quantam (870027)
      As it's always been Raymond's policy not to name names in incidents like this, and you seem to know, could you say what printer model this was?
      • by ktakki (64573)
        That particular printer was a DeskJet 5600 series. Don't remember the specific model number, but HP drivers and software tends to be common across models in a series (e.g., 5650 and 5652 would use identical drivers). I believe that one of the 5600 series printers has a flash card reader for printing digital photos directly. This one didn't, but the HP software install loaded all that Imaging Center and Share-to-Web cruft anyway.

        The Microsoft KB article [microsoft.com] that came out later that week mentioned that systems
    • and people say linux is complicated...
  • by Marton (24416) on Friday May 04, 2007 @07:28PM (#18996823)
    This pretty much rendered Windows useless (explorer, file open / save dialogs and the IE7 addressbar were not working) if you had software installed for HP cameras, HP scanners, or any HP DeskJet printer that included a card reader.

    Courtesy of JSI FAQ:

    You experience one or more of the following strange behaviors:

    - You are unable to open special folders, like My Documents or My Pictures.

    - Some 3rd party applications hang when accessing My Documents.

    - Office files won't open in Microsoft Office if they are stored in My Documents.

    - Entering an address into Internet Explorer's address bar does nothing.

    - The Send TO context menu has no effect.

    - The plus (+) sign on a folder in Windows Explorer does nothing.

    - Opening a file via an applications File / Open menu causes the application to hang.

    This behavior is caused by a new VERCLSID.EXE binary, which validates shell extensions before Explorer.exe, the Windows Shell, can use them. VERCLSID.EXE is installed by the MS06-015 (908531) security update.

    The following 3rd party applications cause VERCLSID.EXE to hang:

    Hewlett-Packard's Share-to-Web Namespace Daemon ("%ProgramFiles%\hewlett-packard\hp share-to-web\Hpgs2wnd.exe), auto-started from the Registry Run key and the Startup menu, which ships with:

                    HP PhotoSmart software
                    Any HP DeskJet printer that includes a card reader
                    HP Scanners
                    Some HP CD-DVD RWs
                    HP Cameras

    Sunbelt Kerio Personal Firewall which has a feature that prompts when Explorer launches VERCLSID.EXE, but you can configure it not to prompt.

    To workaround this behavior, add the HP shell extension to the VERCLSID.EXE white list:

    1. Open a CMD.EXE window.

    2. Type the following command and press Enter:

    REG ADD "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Sh ell Extensions\Cached" /V "{A4DF5659-0801-4A60-9607-1C48695EFDA9} {000214E6-0000-0000-C000-000000000046} 0x401" /T REG_DWORD /F /D 1

    3. Shutdown and restart your computer.

    NOTE: If you find other COM controls or shell extensions that cause this behavior, you can add them to the white list.

  • I recently helped someone install a home printer from HP, the SMALLEST "driver" installation option was 400 MEGABYTES, it defaulted to over 800 megs!

    That's just insane.

    Now multiply that by all the different revisions and patches of the HP drivers, and consider testing each Windows/Application patch against it (on every language, for every version).

    You could deforest the planet with test pages before you hit every code path.
  • Speaking of Explorer Shell extensions, recent OS X converts may be curious about how Finder extensions work.

    One might assume that the Finder extension framework is sprinkled with all sorts of Cocoa goodness, where objects are magically discovered, loaded, and consumed by Finder though some thoughtfully conceived Objective-C interfaces/protocols.

    Nope. It's COM, complete with IUnknowns and HRESULTs, UUIDs and E_FAILs. (The headers are provided by Microsoft). Finder is, after all, just a plain old C++ appli

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