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OpenAdvisories
High LSN-0077-1 1 CVE

Kernel Live Patch Security Notice

Published May 17, 2021 · Updated Jun 3, 2026

Ecosystem: Ubuntu

Summary

Vincent Dehors discovered that the shiftfs file system in the Ubuntu Linux
kernel did not properly handle faults in copy_from_user() when passing
through ioctls to an underlying file system. A local attacker could use
this to cause a denial of service (memory exhaustion) or execute arbitrary
code.(CVE-2021-3492)

Fixed packages 7

ReleasePackageFixed in
Ubuntu · Pro 18.04 LTS Pro:18.04:LTS linux-gke-5.4 5.4.0-1042.44~18.04.1
Ubuntu · Pro 18.04 LTS Pro:18.04:LTS linux-gkeop-5.4 5.4.0-1014.15~18.04.1
Ubuntu · Pro 18.04 LTS Pro:18.04:LTS linux-hwe-5.4 5.4.0-72.80~18.04.1
Ubuntu · Pro 20.04 LTS Pro:20.04:LTS linux 5.4.0-72.80
Ubuntu · Pro 20.04 LTS Pro:20.04:LTS linux-gcp 5.4.0-1042.45
Ubuntu · Pro 20.04 LTS Pro:20.04:LTS linux-gke 5.4.0-1042.44
Ubuntu · Pro 20.04 LTS Pro:20.04:LTS linux-gkeop 5.4.0-1014.15

Vulnerabilities 1

  • High 8.8
    CVE-2021-3492 Public exploit

    Ubuntu linux kernel shiftfs file system double free vulnerability

    Shiftfs, an out-of-tree stacking file system included in Ubuntu Linux kernels, did not properly handle faults occurring during copy_from_user() correctly. These could lead to either a double-free situation or memory not being freed at all. An attacker could u…

    Ubuntu Linux kernel linux-raspi2 linux-hwe Linux Ubuntu

References

  • report
    https://ubuntu.com/security/CVE-2021-3492