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by delamon 38 days ago
How would've memory safety helped here?
2 comments
Mindless2112 38 days ago
In CHERI, for example, pointers have permissions. The pointer to the COW memory would not have the "write" permission.

I could be misunderstanding the bug, of course.

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delamon 38 days ago
If you "forget" to mark COW memory pointer as no-write, the net effect would be same, would it not? If I'm reading the diff correctly, the problem was that code missed to mark some pages as shared (aka no-write).
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Mindless2112 38 days ago
A fair point...

I thought the bug was a missing check for the COW flag, but looking at it again it seems it was missing both setting and checking the flag.

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delamon 38 days ago
Apparently it is both...
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tatersolid 37 days ago
Because “Page-cache write into any readable file” is a memory safety bug? All of these recent Linux LPEs are memory safety issues.
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