Post #1882961
2026-04-30 03:46 UTC
Why did expert eyes, along with a plethora of automated analysis tools, miss this critical flaw for so long?
Because so much of everything involved in that bug being possible is wrong that it just doesn't stand out to scrutiny.
But generally, in-place modification should be avoided unless it's actually necessary. It's way too error prone to reason about without tools for help modeling it (the typesystem can be such a tool, in a number of languages).
This scenario prompts a radical re-evaluation of current code review processes, security tool efficacy, and perhaps even the paradigms we use for kernel development.
Yes, that thing people have been saying for around 50 years by now.
To call UNIX "not up to the current state of the art" is to make a very generous understatement.
Replies (1)
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@lispi314@udongein.xyz 2026-04-30 03:50
Lastly, the silent threat of LPEs cannot be overstated. Unlike network vulnerabilities that might be blocked at the firewall, LPEs often require initial system access. However, once an attacker gains a foothold, even as an unprivileged user, ‘Copy Fail’ offers a straightforward path to full system compromise. This capability can bypass many layered perimeter defenses, turning a minor breach into a full-blown catastrophe. Incidentally vindicating everyone who insisted on proper virtualization for isolation between things (and avoiding the essentially-unauditable colossal attack surface of the Linux kernel). Would you look at that, the Qubes people were right again.