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Bug Linux Hardware

Matthew Garrett Has a Fix To Prevent Bricked UEFI Linux Laptops 74

Posted by timothy from the and-it-can-be-yours-for-free dept.
hypnosec writes "UEFI guru Matthew Garrett, who cleared the Linux kernel in Samsung laptop bricking issues, has come to rescue beleaguered users by offering a survival guide enabling them to avoid similar issues. According to Garrett, storage space constraints in UEFI storage variables is the reason Samsung laptops end up bricking themselves. Garrett said that if the storage space utilized by the UEFI firmware is more than 50 percent full, the laptop will refuse to start and ends up being bricked. To prevent this from happening, he has provided a Kernel patch."
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Matthew Garrett Has a Fix To Prevent Bricked UEFI Linux Laptops More

Matthew Garrett Has a Fix To Prevent Bricked UEFI Linux Laptops

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  • more than 50 per cent full = fail is bad (Score:5, Insightful)

    by Joe_Dragon ( 2206452 ) on Sunday March 24, 2013 @02:57PM (#43264785)

    more than 50 per cent full = fail is bad and Samsung needs to come out with a bios update to fix that.

    • Re:more than 50 per cent full = fail is bad (Score:4, Interesting)

      by SuricouRaven ( 1897204 ) on Sunday March 24, 2013 @03:24PM (#43264919)

      Something like this should never have gotten through testing. Samsung must have tested using only a single OS or a closely related family (ie, Windows) - and that is no way to test if a piece of code is going to behave under all circumstances.

      • Re:more than 50 per cent full = fail is bad (Score:5, Informative)

        by ais523 ( 1172701 ) <ais523(524\)(525)x)@bham.ac.uk> on Sunday March 24, 2013 @04:44PM (#43265369)
        The same bug can brick Samsung laptops on Windows too. It's just that it was noticed on Linux first.

      • Something like this should never have gotten through testing. Samsung must have tested using only a single OS or a closely related family (ie, Windows) - and that is no way to test if a piece of code is going to behave under all circumstances.

        Something like this should never have gotten through design. "Oh, I'm sure nothing will actually try to store nearly as much data in the nonvolatile storage region as the system offers to store, it'll be fine!" is Not a valid plan. Obviously, any finite storage device cannot fulfill arbitrary storage demands; but that's why you have a graceful way of saying 'sorry, no more space', rather than silently accepting the attempt and then falling over dead.

    • We've put error logging in our products, and had an upper limit on how much data it could write, then started a circular buffer, then beat the hell out of it to make sure it ran fine.

      So, too, for basically any data storage. This was just sloppy on somebody's part.

    • Unfortunately you've already got +5 insightful so I can't mod you +1 funny. Unless you weren't trying to be funny, in which case I'd mod you +1 ironic.

      (Hint to people who don't get it: UEFI is a replacement to BIOS. There's no such thing as a 'BIOS' with UEFI.)

    • It depends on the cpu and the manufacturing.... (Score:3, Interesting)

      by Anonymous Coward

      procedure. Some ARM chips have bootstrap code that will talk to a usb device (i.e. looks like a serial port, sort of), and there is a program that lets you load the initial software no matter what's in flash. That usb port might just be a header or a bunch of pads on the cpu.

      With other devices you have to go into a jtag port, (i.e. a header or perhaps just solder pads) load a tiny program into ram, and use THAT to program the flash.

      If they build them with empty flash, there has to be a way to do the initi

    • Re: (Score:3, Insightful)

      by LordLucless ( 582312 )

      If they can, they weren't bricked in the first place. That's what "bricked" means.

      • If they can, they weren't bricked in the first place. That's what "bricked" means.

        Yay! Can we get into an argument as to what bricked means?

        I have a friend with a reflow station, so I can replace busted chips. So *your* hardware isn't *truly* bricked. Etc.

        • Yay! Can we get into an argument as to what bricked means?

          Yay! Let's make it a relative term. I've got a friend who's an idiot. For him, hitting the off switch "bricks" the phone, cause he can't figure out how to fix it from that state.

  • If it's bricked... (Score:2, Interesting)

    by Anonymous Coward

    Just sue on the small claims court.

    You pay like 35 pounds to issue the legal challenge, and you almost automatically win because the problem is due to a defective product.

    Samsung on the other hand will have to show as represented by some lawyer, and has to pay everything.

    If it doesn't show, they will get a decision by default, which is almost the same...

    Why do you think companies do replace items like that instead of flatly refusing?

    Because they can't afford the bad publicity and the continuously court audi

    • Re: (Score:2)

      by Nemyst ( 1383049 )
      Most companies don't ever bother showing up to small claims. Unless the item you're claiming a replacement/repair on is really, really expensive, it's usually more cost-effective for them to get the default decision and pay up than to get a representative in court.

      They largely do this because few people go through the hassle of using small claims court in the first place. It's a bit more complicated than just paying a nominal fee, though that depends on your country's laws, but it's usually worth it.

  • KISS (Score:3)

    by gmuslera ( 3436 ) on Sunday March 24, 2013 @04:04PM (#43265131) Homepage Journal
    The fix is in the wrong place. Is basically broken hardware, something that run as root/admin (intended or not) could brick them at any time. Is a problem just waiting to happen, avoiding them is the right solution.

    • > The fix is in the wrong place.

      Yes, of course, but only Samsung can put it in the right place. At least this is a workaround for people who already made the mistake of buying one of these pieces of junk.

      • These devices came out less than 2 years ago. So they are all still under warranty. Brick them, bring them back to the shop, get a refund, and buy a non-broken device instead.
    • Not for people owning the hardware that want to be able to use it without the risk of bricking it until Samsung comes out with a fixed UEFI (if they ever do).
      • Why do they keep the hardware? Simply get them exchanged for non-broken hardware.
        • Probably because they are unaware of the problem. Better to have a "temporary" fix in the kernel so that _that_ day these people tries to install Linux they don't get bricked devices. Not every one follows the tech news you now.

    • Re: (Score:3)

      by sjames ( 1099 )

      It's more accurately a work-around. It's certainly in the wrong place and ultimately not "the right thing", but has the advantage that it doesn't depend on a potentially unwilling or unable party to at least get it to not brick. As such, it may be 'the best we can do without Samsung' and as such, it's useful.

      It also adds a bit of shame factor. See that Samsung? Some guy sitting in his office can make your hardware work better (with Linux) than your own engineers. How sad is that?!

      If that doesn't make someon

      • If that doesn't make someone at Samsung beet red in the face and desperate to release a properly corrective patch, they deserve to lose in the market.

        Maybe it does, but that still doesn't mean that a fix will be coming. It's not as if developing the fix was expensive, but you've got to consider all the overhead: meetings, heavy testing procedures, etc.

        • Re: (Score:2)

          by sjames ( 1099 )

          Meetings perhaps, but clearly there's not much in the way of testing procedures if a big ugly bug like that got out. Even if there is a lot of testing and this was an anomaly, what';s the patch going to do, double dog brick the laptop?

          • The purpose of these test procedures is not to find bugs (they didn't find this bricking issue afterwards), but it's to delay fixes, if ever a bug is found.

            Case in point: a large Luxembourgish bank [www.bcee.lu] encountered such an issue in their homebanking product (login impossible with some of the Luxtrust smartcard products). The broken version was put online beginning of June 2012 and customers were complaining already within days afterwards. Before the end of Une, it was known (by customers) what the problem was (

  • Why do people trust Samsung software? (Score:1)

    by Anonymous Coward

    Seriously. Anything they can write code for will be buggy, insecure and crap.

  • English for Slashdot editors (Score:4, Funny)

    by wonkey_monkey ( 2592601 ) on Sunday March 24, 2013 @06:26PM (#43265963) Homepage

    According to Garrett, storage space constraints in UEFI storage variables is the reason Samsung laptops end up bricking themselves.

    Is? Is?

    • According to Garrett, storage space constraints in UEFI storage variables is the reason Samsung laptops end up bricking themselves.

      Is? Is?

      I think your one of them Gramer-Nazi's who is always wanting to correct other people's posting.
      Just sit on you're hands for one's!

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