CVE-2023-4611: Use after free race between mbind() and vma-locked page fault

Severity: medium (CVSS 6.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2023-08-29 · updated 2026-09-11
Weakness: CWE-416

Description

A use-after-free flaw was found in mm/mempolicy.c in the memory management subsystem in the Linux Kernel. This issue is caused by a race between mbind() and VMA-locked page fault, and may allow a local attacker to crash the system or lead to a kernel information leak.

Affected products

Linux kernel: from 6.4 before 6.4.8; 6.5-rc1, 6.5-rc2, 6.5-rc3 — fixed in 6.4.8

How to fix

Upgrade to a fixed version: Linux kernel 6.4.8. Check the vendor advisory for mitigations.

References

https://access.redhat.com/security/cve/CVE-2023-4611
https://bugzilla.redhat.com/show_bug.cgi?id=2227244
https://www.spinics.net/lists/stable-commits/msg310136.html
https://access.redhat.com/security/cve/CVE-2023-4611
https://bugzilla.redhat.com/show_bug.cgi?id=2227244
https://www.spinics.net/lists/stable-commits/msg310136.html

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