PT-2026-4475 · Linux+1 · Linux Kernel+1

CVE-2025-71159 · Published 2025-01-01 · Updated 2026-01-24

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 Linux kernel contains a flaw within the btrfs subsystem, specifically in the btrfs get or create delayed node() function. A previous commit altered the order of operations, removing a necessary memory barrier. This change allowed for a potential race condition where a thread could attempt to increment a reference count before it was properly initialized, leading to a refcounting bug and a use-after-free warning. The issue stems from the interaction between setting the reference count for a delayed node and setting the btrfs inode->delayed node pointer. The fix involves restoring the original order of operations to re-establish the necessary memory barrier. The function btrfs get or create delayed node() is involved in the process.

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

Exploit

Use After Free

Weakness Enumeration

CWE-416

Related Identifiers

BDU:2026-08875

CVE-2025-71159

Affected Products

Linux Kernel

Btrfs

References · 17

• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/71xxx/CVE-2025-71159.json · Exploit
• https://git.kernel.org/stable/c/c8385851a5435f4006281828d428e5d0b0bbf8af · Patch
• https://security-tracker.debian.org/tracker/CVE-2025-71159 · Vendor Advisory
• https://osv.dev/vulnerability/DEBIAN-CVE-2025-71159 · Vendor Advisory
• https://ubuntu.com/security/CVE-2025-71159 · Vendor Advisory
• https://osv.dev/vulnerability/UBUNTU-CVE-2025-71159 · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2025-71159 · Vendor Advisory
• https://git.kernel.org/stable/c/83f59076a1ae6f5c6845d6f7ed3a1a373d883684 · Patch
• https://nvd.nist.gov/vuln/detail/CVE-2025-71159 · Security Note
• https://bdu.fstec.ru/vul/2026-08875 · Security Note
• https://osv.dev/vulnerability/BELL-CVE-2025-71159 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2025-71159 · Security Note
• https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git · Note
• https://git.kernel.org/linus/83f59076a1ae6f5c6845d6f7ed3a1a373d883684 · Note
• https://twitter.com/CVEnew/status/2015086222994018669 · Twitter Post