PT-2021-4122 · Linux+3 · Linux Kernel+3

Christophe Leroy · Published 2021-06-18 · Updated 2023-05-17 · CVE-2021-38200

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 5.12.13

Description The issue is related to a NULL pointer dereference in the arch/powerpc/perf/core-book3s.c file of the Linux kernel. This can be exploited by local users to cause a denial of service (perf instruction pointer NULL pointer dereference and OOPS) via a "perf record" command, on systems with perf event paranoid=-1 and no specific PMU driver support registered.

Recommendations For Linux kernel versions prior to 5.12.13, update to version 5.12.13 or later to resolve the issue. As a temporary workaround, consider restricting access to the "perf record" command to minimize the risk of exploitation. Additionally, setting perf event paranoid to a value other than -1 may also help mitigate the risk.

Fix

DoS

NULL Pointer Dereference

Weakness Enumeration

CWE-476

Related Identifiers

ALT-PU-2021-2050

ALT-PU-2021-2199

ALT-PU-2021-2315

ALT-PU-2021-2326

ALT-PU-2021-2330

ALT-PU-2021-3481

ALT-PU-2022-1240

ALT-PU-2022-1419

ALT-PU-2022-1421

ALT-PU-2023-1814

AZL-6584

BDU:2021-04712

CVE-2021-38200

USN-5070-1

Affected Products

Alt Linux

Linuxmint

Linux Kernel

Ubuntu

References · 26

• https://github.com/torvalds/linux/commit/60b7ed54a41b550d50caf7f2418db4a7e75b5bdc · Patch
• https://osv.dev/vulnerability/AZL-6584 · Vendor Advisory
• https://ubuntu.com/security/CVE-2021-38206 · Vendor Advisory
• https://ubuntu.com/security/CVE-2021-38207 · Vendor Advisory
• https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.12.13 · Vendor Advisory
• https://ubuntu.com/security/CVE-2021-22543 · Vendor Advisory
• https://ubuntu.com/security/CVE-2021-38200 · Vendor Advisory
• https://ubuntu.com/security/CVE-2021-38198 · Vendor Advisory
• https://osv.dev/vulnerability/USN-5070-1 · Vendor Advisory
• https://ubuntu.com/security/CVE-2020-26541 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2021-38200 · Security Note
• https://ubuntu.com/security/CVE-2021-34693 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2021-38200 · Security Note
• https://osv.dev/vulnerability/UBUNTU-CVE-2021-38200 · Vendor Advisory
• https://bdu.fstec.ru/vul/2021-04712 · Security Note