What’s Vulnerable › Vulnerabilities

CVE-2023-3640: Kernel: x86/mm: a per-cpu entry area leak was identified through the init_cea_offsets function when prefetchnta and prefetcht2 instructions being used for the per-cpu entry area mapping to the user space

• Severity: high (CVSS 7.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.8% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2023-07-24 · updated 2026-07-21
• Weakness: CWE-385

Description

A possible unauthorized memory access flaw was found in the Linux kernel's cpu_entry_area mapping of X86 CPU data to memory, where a user may guess the location of exception stacks or other important data. Based on the previous CVE-2023-0597, the 'Randomize per-cpu entry area' feature was implemented in /arch/x86/mm/cpu_entry_area.c, which works through the init_cea_offsets() function when KASLR is enabled. However, despite this feature, there is still a risk of per-cpu entry area leaks. This issue could allow a local user to gain access to some important data with memory in an expected location and potentially escalate their privileges on the system.

Affected products

• Linux kernel: all versions
• Red Hat Enterprise Linux: 8.0, 9.0

References

• https://access.redhat.com/errata/RHSA-2023:6583
• https://access.redhat.com/security/cve/CVE-2023-3640
• https://bugzilla.redhat.com/show_bug.cgi?id=2217523
• https://access.redhat.com/security/cve/CVE-2023-3640
• https://bugzilla.redhat.com/show_bug.cgi?id=2217523

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