PT-2025-7951 · Linux+2 · Linux Kernel+2

Chen Jingwen · Published 2025-02-26 · Updated 2025-05-21 · CVE-2021-47640

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 versions prior to 5.15.0-12267-gdebe436e77c7

Description The issue is related to the powerpc/kasan component of the Linux kernel, where the shadow's page table is not updated correctly when PTE RPN SHIFT is 24 and PAGE SHIFT is 12. This causes false positives and false negatives. The problem is fixed by bringing the logic of kasan early shadow page entry to the affected area.

Recommendations For Linux kernel versions prior to 5.15.0-12267-gdebe436e77c7, update to a version that includes the fix for the powerpc/kasan issue.

Fix

Memory Corruption

Weakness Enumeration

CWE-787

Related Identifiers

CVE-2021-47640

Affected Products

Astra Linux

Linux Kernel

Red Os

References · 16

• https://git.kernel.org/stable/c/f39a3309393a4a484532f6ba745c6acbcfe06115 · Patch
• https://git.kernel.org/stable/c/e3d157a4b4f4e0268c98be5b7013bf4b31234bb6 · Patch
• https://osv.dev/vulnerability/UBUNTU-CVE-2021-47640 · Vendor Advisory
• https://git.kernel.org/stable/c/7f19245c3647afea8c7c41f795506ef70f64b9f2 · Patch
• https://git.kernel.org/stable/c/5a3d8f3192a409893c57808cc935e16484df1068 · Patch
• https://git.kernel.org/stable/c/dd75080aa8409ce10d50fb58981c6b59bf8707d3 · Patch
• https://cve.org/CVERecord?id=CVE-2021-47640 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2021-47640 · Security Note
• https://ubuntu.com/security/CVE-2021-47640 · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2021-47640 · Vendor Advisory
• https://osv.dev/vulnerability/DEBIAN-CVE-2021-47640 · Vendor Advisory
• https://git.kernel.org/stable/c/de56beace6648065d404cd9835aa7d30e3df519d · Patch
• https://security-tracker.debian.org/tracker/CVE-2021-47640 · Vendor Advisory
• https://twitter.com/CVEnew/status/1898276757628940550 · Twitter Post
• https://git.kernel.org/linus/dd75080aa8409ce10d50fb58981c6b59bf8707d3 · Note