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Bug Windows Hardware Linux

Samsung Laptop Bug Is Not Linux Specific 215

Posted by timothy
from the using-french-or-korean-does-it-too dept.
First time accepted submitter YurB writes "Matthew Garrett, a Linux kernel developer who was investigating the recent Linux-on-Samsung-in-UEFI-mode problem, has bricked a Samsung laptop using a test userspace program in Windows. The most fascinating part of the story is on what is actually causing the firmware boot failure: 'Unfortunately, it turns out that some Samsung laptops will fail to boot if too much of the [UEFI] variable storage space is used. We don't know what "too much" is yet, but writing a bunch of variables from Windows is enough to trigger it. I put some sample code here — it writes out 36 variables each containing a kilobyte of random data. I ran this as an administrator under Windows and then rebooted the system. It never came back.'"
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Samsung Laptop Bug Is Not Linux Specific

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  • by neonsignal (890658) on Saturday February 09, 2013 @06:19PM (#42846085)

    The reason it was noticed on Linux is because a portion of this UEFI space is being used to keep a non-volatile copy of the most recent kernel log messages (so that on a crash event, it is easier to find out what happened).

  • by Anonymous Coward on Saturday February 09, 2013 @06:37PM (#42846193)

    Add that script to the payload malware usually carries, and spread it around, a few thousands bricks later, the negative publicity is sure to kill this whole UEFI thing, or at least force the hardware makers to include linux in their testing.

    Yes, absolutely. Because people owning these devices would love nothing more than sacrificing them and their time and data to this cause.

  • by Forever Wondering (2506940) on Saturday February 09, 2013 @07:22PM (#42846529)
    From the scant details, it appears Samsung didn't provide enough storage [of whatever type] to be able to store the UEFI variables that one could reasonably be expected to store. And/or when that storage ran out [or hit a percentage threshold], simply failed to prevent the bricking with a limit check and refuse to store the new information [returning an error code instead]. It's unclear what's truly happening, but it seems that the extra UEFI data goes somewhere and scribbles on some NV memory that it shouldn't [which may have nothing to do with secure boot].
  • Re:Free Laptops? (Score:5, Insightful)

    by Skapare (16644) on Saturday February 09, 2013 @07:25PM (#42846559) Homepage

    These steps are actually NOT supposed to brick them. It is thus a proven manufacturing defect. So Samsung is obligated to "repair or replace". An external (JTAG) reflash of the ROM should be able to fix it. Samsung should also fix it by reprogramming the ROM code to perform UEFI correctly.

  • by RichMan (8097) on Saturday February 09, 2013 @07:52PM (#42846713)

    > The title of the article is "Samsung Laptop Bug Is Not Linux Specific" for fuck's sake. Learn to read.

    Sorry, but you need to learn to think.....

    Sure the bug is not Linux specific. But Linux was the first to expose it. If they had tested on Linux they would have known it was broken and could have fixed it before releasing the hardware.
    That is my point. Linux gives more hardware coverage and can expose bugs that might not be found otherwise. Linux provides a pretty much free test load for the hardware.

    Any test house should be very very happy to have a pretty much free (only cost is small time to setup boot) second test suite for the hardware.

  • by LordLimecat (1103839) on Saturday February 09, 2013 @08:43PM (#42847027)

    Linux runs happily on all sorts of crappy hardware because somewhere, at some point, a linux dev did a lot of heavy lifting to make that happen, not because linux magically works with all hardware.

  • by Anonymous Coward on Saturday February 09, 2013 @08:55PM (#42847105)

    Riiiiiight. Like there's nothing to be gained by an over zealous anti-UEFI coder writing a virus to accomplish what all the sound logic presented can not: making UEFI cost prohibitive due to RMA's and ad press.

  • by gweihir (88907) on Sunday February 10, 2013 @01:02AM (#42848165)

    The Linux folks actually read and understand the documentation and then use the mechanisms described. The Windows-folks are usually not so capable.

  • by MaskedSlacker (911878) on Sunday February 10, 2013 @02:57AM (#42848589)

    Right, instead of fucking up Windows (which they could have already done) they fuck up your firmware, and you honestly think end users would even know the damned difference. Pass the pipe please.

    Maybe you should stop smoking that, it's damaging your critical thinking skills.

    The users are not the one receiving a message in this scenario. The manufacturer is the one receiving the message. It works like this:

    1) Unethical hacker writes virus to brick Samsung laptops.
    2) Thousands of Samsung laptops get sent in under warranty for repair because they inexplicably (from the users' perspective) stopped booting.
    3) Samsung bean counters notice that UEFI models have an unacceptably high rate of failure under warranty.
    4) Samsung bean counters decide to kill UEFI models.

  • by silanea (1241518) on Sunday February 10, 2013 @05:58AM (#42849087)

    [...] the negative publicity is sure to kill this whole UEFI thing, [...]

    This is becoming increasingly annoying: Why the hell is there so much hate for UEFI? I run Linux Mint and Windows 7 in a dual-boot setup and frankly I have come to love the speed at which my rig boots since switching to a pure UEFI setup. For whatever reason BIOS-based configurations on the same hardware took ages in comparison. I like UEFI. I do not want anyone to kill it.

    Now, SecureBoot, that is a different beast. I see quite a few uses, eg. preventing 'bad people' from booting anything I did not preapprove on my machine. But as long as I cannot verify which keys and possible backdoors the manufacturer might have put in it is pretty much unusable. I am waiting for the UEFI equivalent of CoreBoot. That would be a real boon.

  • by gerddie (173963) on Sunday February 10, 2013 @08:03AM (#42849353)

    [..]

    I'm going to pick option B however, where RMAs for the model are denied because everyone knows those users destroyed their hardware using that nasty Linux program, and they're not going to get a replacement or refund at all.

    [...]

    In case you didn't RTFS: The laptop was bricked by using a program running on Windows.

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