Kernel: Request random numberfs for syscall stack noise in larger chunks #3125
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Take the next byte and index into the array by that? |
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Given the magnitude of the slowdown, I think the risk of buffering some randomness is acceptable. |
Cuts time needed for `disasm /bin/id` from 2.5s to 1s -- identical to the time it needs when not doing the random adjustment at all. The downside is that it's now very easy to get the random offsets with out-of-bounds reads, so it does make this mitigation less effective.
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This basically made everything a lot faster. |
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Cuts time needed for
disasm /bin/idfrom 2.5s to 1s -- identicalto the time it needs when not doing the random adjustment at all.
The downside is that it's now very easy to get the random offsets
with out-of-bounds reads, so it does make this mitigation less
effective.
--
Not sure if we want this, but it does make syscall-heavy programs much faster.
We can probably get the 2.5s down some more by optimizing the rng code more, but likely not this low.