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

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.

Remediation

Workaround:

  • Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.

Category

7.0
CVSS
Severity: High
CVSS 3.1 •
EPSS 0.14%
Vendor Advisory redhat.com
Affected: Red Hat Red Hat Enterprise Linux 9
Affected: Red Hat Red Hat Enterprise Linux 9
Affected: Red Hat Red Hat Enterprise Linux 6
Affected: Red Hat Red Hat Enterprise Linux 7
Affected: Red Hat Red Hat Enterprise Linux 7
Affected: Red Hat Red Hat Enterprise Linux 8
Affected: Red Hat Red Hat Enterprise Linux 8
Affected: Red Hat Red Hat Enterprise Linux 9
Published at:
Updated at:

References

Frequently Asked Questions

What is the severity of CVE-2023-3640?
CVE-2023-3640 has been scored as a high severity vulnerability.
How to fix CVE-2023-3640?
As a workaround for remediating CVE-2023-3640: Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Is CVE-2023-3640 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2023-3640 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2023-3640?
CVE-2023-3640 affects Red Hat Red Hat Enterprise Linux 9, Red Hat Red Hat Enterprise Linux 9, Red Hat Red Hat Enterprise Linux 6, Red Hat Red Hat Enterprise Linux 7, Red Hat Red Hat Enterprise Linux 7, Red Hat Red Hat Enterprise Linux 8, Red Hat Red Hat Enterprise Linux 8, Red Hat Red Hat Enterprise Linux 9.
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