Ubuntu Disables Spectre/Meltdown Protections
2018年发现的CPU推测执行攻击曾引发广泛关注和修复措施,但这些修复显著降低了性能。近期Ubuntu禁用部分保护机制以提升20%性能。英特尔与Canonical团队达成共识,认为Spectre攻击在GPU层面的缓解不再必要,因已在内核中解决。权衡后认为此类攻击难度高且数据窃取不易,更简单的方式攻击系统更现实。 2025-7-2 11:2:22 Author: www.schneier.com(查看原文) 阅读量:20 收藏

A whole class of speculative execution attacks against CPUs were published in 2018. They seemed pretty catastrophic at the time. But the fixes were as well. Speculative execution was a way to speed up CPUs, and removing those enhancements resulted in significant performance drops.

Now, people are rethinking the trade-off. Ubuntu has disabled some protections, resulting in 20% performance boost.

After discussion between Intel and Canonical’s security teams, we are in agreement that Spectre no longer needs to be mitigated for the GPU at the Compute Runtime level. At this point, Spectre has been mitigated in the kernel, and a clear warning from the Compute Runtime build serves as a notification for those running modified kernels without those patches. For these reasons, we feel that Spectre mitigations in Compute Runtime no longer offer enough security impact to justify the current performance tradeoff.

I agree with this trade-off. These attacks are hard to get working, and it’s not easy to exfiltrate useful data. There are way easier ways to attack systems.

News article.

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Posted on July 2, 2025 at 7:02 AM2 Comments

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文章来源: https://www.schneier.com/blog/archives/2025/07/ubuntu-disables-spectre-meltdown-protections.html
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