PT-2024-11317 · Linux · Linux Kernel

Viresh Kumar · Published 2021-07-01 · Updated 2024-12-26 · CVE-2021-47318

Positive Technologies (AI Summary)

CVSS v3.1

7.8

High

Base vector

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

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description The issue is related to a use-after-free vulnerability in the arch topology component of the Linux kernel. The topology scale freq tick() function, which is called from scheduler tick(), may use a pointer to struct scale freq data that was previously cleared by topology clear scale freq source(). To resolve this, the RCU update mechanism is used to guarantee race-free updates. The synchronize rcu() function ensures that all RCU critical sections started before it is called will finish before it returns, allowing the callers of topology clear scale freq source() to free related resources without worrying about their callback being called again.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Use After Free

Weakness Enumeration

CWE-416

Related Identifiers

BDU:2025-07325

CVE-2021-47318

Affected Products

Linux Kernel

References · 14

• https://cve.org/CVERecord?id=CVE-2021-47318 · Security Note
• https://osv.dev/vulnerability/DEBIAN-CVE-2021-47318 · Vendor Advisory
• https://bdu.fstec.ru/vul/2025-07325 · Security Note
• https://git.kernel.org/stable/c/ccdf7e073170886bc370c613e269de610a794c4a · Patch
• https://security-tracker.debian.org/tracker/CVE-2021-47318 · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2021-47318 · Vendor Advisory
• https://git.kernel.org/stable/c/83150f5d05f065fb5c12c612f119015cabdcc124 · Patch
• https://ubuntu.com/security/CVE-2021-47318 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2021-47318 · Security Note
• https://osv.dev/vulnerability/UBUNTU-CVE-2021-47318 · Vendor Advisory
• https://lore.kernel.org/linux-cve-announce/2024052131-CVE-2021-47318-fffb@gregkh · Note
• https://git.kernel.org/linus/83150f5d05f065fb5c12c612f119015cabdcc124 · Note
• https://t.me/cvenotify/105545 · Telegram Post
• https://kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.13.4 · Note