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Re: kernel module loading vs securelevel

On Sat, 16 Oct 2010, David Holland wrote:

> And also make the "blessed" directory itself immutable?  :)

As I recall the semantics of immutable are such that this isn't
necessary to protect modules that are present at boot time (that is,
they can't be unlinked/renamed/etc.), and if there are autoloadable
modules whose names aren't present at boot time, they'll fail the

I've already misread the code here once, but...

As far as I can tell, each time a module_autoload call is made, if the module is neither built-in nor passed in by the boot loader, the code will attempt to load it via a call to kobj_load_vfs() which has path as an argument. It doesn't appear to me that there is any pre-approved list of acceptable objects that can be loaded from the file system.

BTW, does the immutable flag prevent one from using an immutable directory as the mount-point for some other file system? Hmmm...

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