CVE-2023-53254: cacheinfo: Fix shared_cpu_map to handle shared caches at different levels

Severity: high (CVSS 7.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-09-15 · updated 2026-08-04
Weakness: CWE-125

Description

In the Linux kernel, the following vulnerability has been resolved: cacheinfo: Fix shared_cpu_map to handle shared caches at different levels The cacheinfo sets up the shared_cpu_map by checking whether the caches with the same index are shared between CPUs. However, this will trigger slab-out-of-bounds access if the CPUs do not have the same cache hierarchy. Another problem is the mismatched shared_cpu_map when the shared cache does not have the same index between CPUs. CPU0 I D L3 index 0 1 2 x ^ ^ ^ ^ index 0 1 2 3 CPU1 I D L2 L3 This patch checks each cache is shared with all caches on other CPUs.

Affected products

Linux kernel: before 6.1.18; from 6.2 before 6.2.5 — fixed in 6.1.18, 6.2.5

How to fix

Upgrade to a fixed version: Linux kernel 6.1.18, 6.2.5. Check the vendor advisory for mitigations.

References

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