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Several vulnerabilities have been discovered in the Linux kernel

576 points · 408 comments · luispa

john_strinlai · 1790902914 · focus · HN ↗
note that _any_ bugfix is assigned a cve, which makes for big numbers.
>“Due to the layer at which the Linux kernel is in a system, almost any bug might be exploitable to compromise the security of the kernel… Because of this, the CVE assignment team is overly cautious and assign CVE numbers to any bugfix that they identify.”
<a href="https://docs.kernel.org/process/cve.html" rel="nofollow">https://docs.kernel.org/process/cve.html
"number of cves" is a useless metric, especially when it comes to the kernel.
1. SAI_Peregrinus · 1790903533 · focus · HN ↗
  Tautologically every bug can legitimately be assigned a CVE, since every bug prevents some feature from working as intended. It's therefore a denial of service, which by the definition of the CVE system using CVSS means every bug is at least a 1/Low level vulnerability to CVSS v4.0.
  If you're willing to stretch, missing but planned features also deny the use of said features since they haven't been added yet, and so are CVSS 1/Low vulnerabilities.
  Resume-driven development for security researchers has never been easier!
  1. jeroenhd · 1790922696 · focus · HN ↗
    Loads of bugs aren't CVE-worthy. If you tell the computer to make a light green but it makes the light red, that's a bug but no DoS or other CVE-worthy bug.
    However, the Linux kernel is supposed to run any userland program without crashing, so anything that crashes the kernel is a local DoS and there are a lot of them. It's also supposed to shield processes from each other and maintain privilege levels correctly, so many incorrect memory leaks are also CVE worthy. Whether a CVE applies depends on the people and programs using the kernel, and the kernel team can't read your code to tell you if it applies or not.
    People reading CVEs wrong ("it's got a high number so we must patch within a day") must be going crazy over this, but the point of CVEs is to let you make judgement calls, not to be a cool statistic about how secure something is.
    Most CVEs are irrelevant to most people, that's always been the case.
    somat · 1790928516 · focus · HN ↗
    "why did the ship crash?"
    Unpatched bug, wrong color lights.
    Yes, it is a bit of a stretch, I desperately hope programmable navigation lights are not a thing. And I also don't think every bug needs a CVE. But in the correct context nearly any bug could be critical.
    seanhunter · 1790929387 · focus · HN ↗
    Computer Weekly in the UK did some pioneering journalism into a helicopter crash[1] that had initially been blamed on the two pilots but seems very likely to have been caused by a failure of a computer system that was controlling the fuelling of the engines. Iirc this system seems to have crashed causing engine failure of both engines in heavy fog, bringing the helicopter down with a loss of everyone on board, however for reasons somewhat unclear, the MOD wanted to cover the failure up by blaming the pilots.
    Now this was a windows system[2] rather than linux but the point remains - if there was an external vulnerability in a crucial control system and this system was part of a network (eg to connect telemetry) then any exploit of that system could result in loss of life.
    [1] <a href="https://www.computerweekly.com/news/1280091718/Chinook-computer-was-positively-dangerous-say-newly-disclosed-MoD-documents" rel="nofollow">https://www.computerweekly.com/news/1280091718/Chinook-compu...
    After an assessment of the Fadec software the Superintendent of Engineering Systems said that the density of deficiencies was so high that the software was unintelligible.
    [2] Which, why? Why build the fuel controller for a helicopter engine on windows?
    rjsw · 1790932267 · focus · HN ↗
    Are you sure that the Chinook used Windows? I have not read this elsewhere.
    There have been documented problems with Windows for Warships.
    seanhunter · 1790939341 · focus · HN ↗
    My memory is ancient so may be flawed but that is what I remember. This seems to be a full chronology of the incident if you’re interested <a href="https://www.computerweekly.com/news/1280096804/Chronology-The-Chinook" rel="nofollow">https://www.computerweekly.com/news/1280096804/Chronology-Th...
    sas224dbm · 1790943160 · focus · HN ↗
    A windows system controlling the refuelling ? Worked in aviation software for a while and the certification for flight control (or similar) systems is subject to rigorous path testing/inspections/approvals etc DO-178C (level A or B likely). Not sure if any windows OS is certified to level A?? Typically certifiable RTOS'es are procured for those purposes
    jeroenhd · 1790940953 · focus · HN ↗
    That's still not cause for a CVE, even if it's a bad bug.

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