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    SubjectRe: [PATCH] kernel: make /proc/kallsyms mode 400 to reduce ease of attacking

    Sorry for being late to join this thread.

    I thought I'd also mention that if you can insert a small amount of
    shell code into the kernel, it's trivial to search kernel memory for
    the symbol table and derive anything else you want from that.

    I wrote some proof of concept code to do this a few years ago[1]. I'm
    pretty sure you could compress this down to a few bytes of assembler.

    (Plus I don't think that removing pointers is a good idea anyway -- it
    just breaks userspace tools, and any real world system is going to be
    running a well-known kernel that can be downloaded from some mirror


    [1] It's a poor example, but in here is code that searched for ksyms
    and kallsyms in 32 bit i386 kernels (files and;a=tree;f=lib;hb=HEAD

    Richard Jones, Virtualization Group, Red Hat
    virt-df lists disk usage of guests without needing to install any
    software inside the virtual machine. Supports Linux and Windows.

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