PT-2024-11081 · Linux+4 · Linux Kernel+4

Syzbot · Published 2021-04-12 · Updated 2025-01-08 · CVE-2021-46972

Positive Technologies (AI Summary)

CVSS v3.1

5.5

Medium

Base vector

AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Name of the Vulnerable Software and Affected Versions Linux kernel versions prior to 5.12.0-rc5

Description The issue arises from the overlayfs not putting temporary dentry when there is a metacopy error, leading to dentry leaks when shutting down the related superblock. This results in busy inodes after unmount of overlay, causing the system to self-destruct in 5 seconds. The fix has been tested with a syzkaller reproducer.

Recommendations For Linux kernel versions prior to 5.12.0-rc5, update to a newer version to mitigate the risk of dentry leaks. At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Memory Leak

Weakness Enumeration

CWE-401

Related Identifiers

ALSA-2024:4211

ALSA-2024:4352

BDU:2025-03589

CESA-2024_4211

CESA-2024_4352

CVE-2021-46972

INFSA-2024_4211

INFSA-2024_4352

RHSA-2024:4211

RHSA-2024:4352

RHSA-2024_4211

RHSA-2024_4352

RLSA-2024:4211

RLSA-2024:4352

RXSA-2024:4211

Affected Products

Almalinux

Centos

Linux Kernel

Red Hat

Rocky Linux

References · 216

• https://osv.dev/vulnerability/RLSA-2024:4211 · Vendor Advisory
• https://git.kernel.org/stable/c/d587cfaef72b1b6f4b2774827123bce91f497cc8 · Patch
• https://errata.almalinux.org/8/ALSA-2024-4352.html · Vendor Advisory
• https://osv.dev/vulnerability/DEBIAN-CVE-2021-46972 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2021-46972 · Security Note
• https://bdu.fstec.ru/vul/2025-03589 · Security Note
• https://osv.dev/vulnerability/RLSA-2024:4352 · Vendor Advisory
• https://osv.dev/vulnerability/UBUNTU-CVE-2021-46972 · Vendor Advisory
• https://git.kernel.org/stable/c/cf3e3330bc5719fa9d658e3e2f596bde89344a94 · Patch
• https://osv.dev/vulnerability/CVE-2021-46972 · Vendor Advisory
• https://errata.almalinux.org/8/ALSA-2024-4211.html · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2021-46972 · Security Note
• https://osv.dev/vulnerability/ALSA-2024:4352 · Vendor Advisory
• https://git.kernel.org/stable/c/eaab1d45cdb4bb0c846bd23c3d666d5b90af7b41 · Patch
• https://errata.rockylinux.org/RLSA-2024:4352 · Vendor Advisory