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

HIGH
7.8
CVSS Score
Published: July 24, 2023 at 03:19 PM UTC
Updated: July 21, 2026 at 07:17 PM UTC
2 products affected across 2 vendorsLinux KernelEnterprise Linux

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Severity
HIGH7.8
Exploit prediction
EPSS 0.8%
SSVC
No known exploit

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

All versions
Vendor states this is fixed in 6 (unaffected)
Vendor states this is fixed in 7 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (3)

VDB Entryx_refsource_REDHATThird Party Advisory
https://access.redhat.com/security/cve/CVE-2023-3640
Issue Trackingx_refsource_REDHATThird Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2217523

SSVC — Action Prioritization

SSVCNo known exploitNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-203CWE-385

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