Messages in this thread |  | | | Date | Wed, 23 Dec 2009 21:29:02 -0500 | | From | Michael Stone <> | | Subject | A basic question about the security_* hooks |
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Dear kernel folks,
There are a variety of places where I'd like to be able to get the kernel to return EPERM more often [1]. Many of these places already have security hooks.
Unfortunately, I don't feel that I can make effective use of these hooks because they seem to be "occupied" by the large mandatory access control frameworks.
I'm hoping that you can tell me why this state of affairs persists.
More specifically, now that LSMs are statically linked, why is it good for the security hooks to call into a single monolithic "security_ops" struct instead of cheaper and simpler alternatives?
In particular, what would be worse about a kernel in which each security hook contained nothing but conditionally-compiled function calls to the appropriate "real" implementation functions with early-exit jumps on non-zero return codes?
Thanks,
Michael
[1]: Two examples include my recent network-privileges patches and Eric Biederman's suggestions on how to make unprivileged unshare(CLONE_NEWNET) safe. I have little doubt that I'd think of more if I thought that the security hooks were accessible to me.
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