Messages in this thread | | | From | "Albert D. Cahalan" <> | Subject | Re: QUESTION: 32-bit UIDs and Linux 2.3 | Date | Fri, 9 Jul 1999 23:19:41 -0400 (EDT) |
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Marc Mutz writes: > Albert D. Cahalan wrote:
>> Suggested rules: >> >> 1. Always allow 32-bit calls. >> >> 2. Always have 16-bit calls in the kernel. (see below) >> >> 3. Let unprivileged processes get garbage UID values. The software >> isn't very dangerous, and it might work fine. >> >> 4. If any large UID is ever set for any process, privileged processes >> must not be allowed to make any 16-bit calls. Log the problem, >> stop the process, and return failure if the process continues. >> >> 5. Have a run-time config option to kill any privileged process that >> tries to use a 16-bit call. >> >> 6. Have a run-time config option to allow 16-bit calls from privileged >> processes that are not setuid. > > Hmm, altough I'm fully aware of these points being restricted to UID > issues, it is very reminiscent of the win16->win32 transition and all > its pain (& overhead). Esp. items 4-6 seem rather ugly to me. Was this > meant to be a temporary workaround - maybe introduced in 2.3/2.4 and > then 2.6/3.0 support only 32bit-UID - or do such things become legacy > ballast until a 'Linux NT' is written from scratch to remove all of > this?
After transition, points 5 and 6 are no overhead. (they only affect the use of old calls) Point 4 is a tiny bit of overhead for the detection of large UID values, but that can be eliminated at some point: just assume they will be used, so all privileged processes must use the new calls unless allowed by point 6.
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