Messages in this thread | | | Date | Thu, 12 Jan 2012 19:37:07 -0600 | Subject | Re: [PATCH PLACEHOLDER 1/3] fs/exec: "always_unprivileged" patch | From | Will Drewry <> |
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On Thu, Jan 12, 2012 at 7:11 PM, Andrew Lutomirski <luto@mit.edu> wrote: > (Also, preventing dropping of privileges will probably make a patch > more complicted -- I'll have to find and update all the places that > allow dropping privileges.)
An alternative approach might be that the restricted bit drops all privileges that allows privilege changes in either direction. E.g., - set restricted bit -- adds a check anywhere MNT_NOSUID is -- sets securebit to SECURE_NOROOT|..LOCKED -- drops CAP_SETUID, CAP_DAC_OVERRIDE, ... -- set the caps bounding set to the minimum the restricted bit allows
That may deviate from the intent (by re-using caps), but it could keep some of the privilege transition checking code the same.
Just a thought, will
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