A new Linux vulnerability known as 'Looney Tunables' enables local attackers to gain root privileges by exploiting a buffer overflow weakness in the GNU C Library's ld.so dynamic loader.

From BeepingComputer.

  • qaz@lemmy.world
    125·
    9 months ago

    A new Linux vulnerability known as ‘Looney Tunables’ enables local attackers to gain root privileges by exploiting a buffer overflow weakness in the GNU C Library’s ld.so dynamic loader.

    It’s always memory management

      • GreyBeard@lemmy.one
        621·
        9 months ago

        It’s certainly why it is being used to build browsers and OSs now. Those are places were memory management problems are a huge problem. It probably doesn’t make sense for every match 3 game to be made in Rust, but when errors cause massive breaches or death, it’s a lot safer than C++, taking human faulability into account.

        • AggressivelyPassive@feddit.de
          221·
          9 months ago

          Question would be rather: why is something like C++ needed for such simple apps?

          C++ seems to be in that weird in-between place of offering high level features to be reasonable productive, but still doesn’t enforce/guarantee anything to make these features safe. I’d argue, very few programs need that. Either you’re writing business stuff, then you want safety (Java, C#, rust), or you’re writing embedded/low level stuff, then you want control (C, ASM).

          The room for “productive, but not interested in safety” is basically just AAA games, I guess.

          • intelati@programming.dev
            111·
            9 months ago

            C is almost the old “steady” standard now it feels like. It’s so flexible and the frameworks are already built…

            • entropicdrift@lemmy.sdf.org
              15·
              9 months ago

              …except that we also end up with cracks in our foundations like this exploit constantly being exposed as a result of all that C

          • teawrecks@sopuli.xyz
            7·
            9 months ago

            Well you’re not going to write asm if you want your code to be portable at all, and believe it or not C++ has a lot of features to help you not shoot yourself in the foot that C doesn’t have (ex. OOP, RAII, smart pointers).

            C wasn’t really designed with dynamic memory management in mind. It was designed for someone who has absolute control over a machine and all the memory in it. malloc() and free() are just functions that some environments expose to user mode processes, but C was never designed to care where you got your memory or what you do with it.

          • lloram239@feddit.de
            10·
            9 months ago

            C has no memory protection. If you access to the 10th element of a 5 element array, you get to access whatever is in memory there, even if it has nothing to do with that array. Furthermore this doesn’t just allow access to data you shouldn’t be able to access, but also the execution of arbitrary code, as memory doesn’t make a (big) difference between data and code.

            C++ provides a few classes to make it easier to avoid those issues, but still allows all of them.

            Ruby/Python/Java/… provide memory safety and will throw an exception, but they manually check it at runtime, which makes them slow.

            Rust on the other side tries to proof as much as it can at compile time. This makes it fast, but also requires some relearning, as it doesn’t allow pointers without clearly defined ownership (e.g. the classic case of keeping a pointer to the parent element in a tree structure isn’t allowed in Rust).

            Adding the safeties of Rust into C would be impossible, as C allows far to much freedom to reliably figure out if a given piece of code is safe (halting problem and all that). Rust purposefully throws that freedom away to make safe code possible.

          • ziviz@lemmy.sdf.orgEnglish
            7·
            9 months ago

            The short answer is Rust was built with safety in mind. The longer answer is C was built mostly to abstract from assembly without much thought to safety. In C, if you want to use an array, you must manually request a chunk of memory, check to make sure you are writing within the bounds of your array, and free up the memory used by your array when completely done using it. If you do not do those steps correctly, you could write to a null pointer, cause a buffer overflow error, a use-after-free error, or memory leak depending on what step was forgotten or done out of order. In Rust, the compiler keeps track of when variables are used through a borrowing system. With this borrowing system the Rust compiler requests and frees memory safely. It also checks array bounds at run-time without a programmer explicitly needing to code it in. Several high-level languages have alot of these safety features too. C# for example, can make sure objects are not freed until they fall out of scope, but it does this at run-time with a garbage collector where Rust borrower rules are done at compile-time.

            • Affine Connection@lemmy.worldEnglish
              1·
              9 months ago

              C was built mostly to abstract from assembly

              That’s actually not true; rather, many modern architectures are designed to allow languages like C to be compiled more easily. Old architectures don’t even have a built-in stack.

          • Michael Murphy (S76)@lemmy.worldEnglish
            5·
            9 months ago

            The compiler enforces “aliasing XOR mutability”; utilizes “move semantics”; has a “borrowing and ownership” model; and requires the programmer to tag their references with “lifetimes”. Array accesses are checked at runtime if they cannot be guaranteed safe at compile-time. Variables passed by value (moved) cannot be reused. Variables cannot be moved or mutated if any borrow to them exists. You may either have only one mutable borrow, or many immutable borrows, but never both. Therefore you cannot mutate an array while iterating on it, and you cannot have two separate unchecked references to the same array. Every function or type that accepts a borrow must be able to annotate the lifetimes of references to ensure that references are always dropped in the correct order to prevent dangling references. Rust requires developing software with discipline using patterns that satisfy all of these constraints.

        • AggressivelyPassive@feddit.de
          492·
          9 months ago

          But it’s harder and easier to spot.

          You’ll never be 100% safe, but a proper lock is better than a “plz no steal” note.

        • lloram239@feddit.de
          51·
          9 months ago

          Dumb stuff in Rust has to be explicitly marked with unsafe. Meaning if you review the code you have to focus on only a couple of lines instead of the whole project.

          You can of course still write lots of other bugs in Rust, but C-style buffer overflows are impossible in Rust, which eliminates the majority of security issues.

    • Eezyville@sh.itjust.worksEnglish
      361·
      9 months ago

      Didn’t Microsoft do a study on security vulnerabilities and found that the overwhelmingly number of bugs was due to memory management?

  • NateNate60@lemmy.ml
    561·
    9 months ago

    It says “sysadmins should prioritise patching”, but… has it been patched yet?

  • Veticia@lemmy.ml
    361·
    9 months ago

    I wonder if this could be used to root previously unrootable Android based devices.

    • palordrolap@kbin.social
      7·
      9 months ago

      Makes me wonder. LMDE got a glibc update too and Mint is very much not leading edge when it comes to non-critical updates.

      Case in point, at roughly the same time as the glibc update, we (LMDE users) were upgraded to the latest Thunderbird, 115.3.1, four or five days after that sub-version came out. That’s the sort of lag we generally see. (115.x was a bit of a surprise too as we’ve been on 102.x, but that’s not strictly relevant here.)

        • palordrolap@kbin.social
          5·
          9 months ago

          I only mentioned the lag to make the point that if we’re getting an update at the same time as Arch that maybe it was an important one.

          Anyone on Mint who finds themselves trying to leap ahead of the default release schedule might want to at least sniff around a different distro or two.

          That said, Flatpaks with later versions are also often available in the provided Software Manager (basically an app store), so that’s a place to look before jumping ship. Hard to tell now, but I think 115 was the Flatpak option while the, uh, default default was 102.