PT-2025-46613 · Linux+3 · Linux Kernel+3

Published 2025-08-18 · Updated 2026-02-24 · CVE-2025-40138

Positive Technologies (AI Summary)

CVSS v2.0

4.6

Medium

Base vector

AV:L/AC:L/Au:S/C:N/I:N/A:C

Name of the Vulnerable Software and Affected Versions Linux kernel versions prior to 6.17.0-rc1-syzkaller-00014-g0e39a731820a

Description The Linux kernel contains a flaw in the f2fs filesystem implementation. Specifically, a NULL pointer dereference can occur within the f2fs check quota consistency() function. This issue arises when comparing quota names without first verifying that they are valid pointers. The problem was identified through syzbot testing and can be triggered by mounting the f2fs filesystem with user quotas enabled, running quotacheck, and then remounting the filesystem with different quota options. The strcmp function is involved in the vulnerability.

Recommendations Update to Linux kernel version 6.17.0-rc1-syzkaller-00014-g0e39a731820a or a later version that includes the fix.

Exploit

Fix

NULL Pointer Dereference

Weakness Enumeration

CWE-476

Related Identifiers

BDU:2025-16140

CVE-2025-40138

USN-8029-1

USN-8029-2

USN-8029-3

USN-8030-1

USN-8048-1

Affected Products

Linuxmint

Linux Kernel

Ubuntu

F2Fs

References · 391

• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/40xxx/CVE-2025-40138.json · Exploit
• https://ubuntu.com/security/CVE-2025-40153 · Vendor Advisory
• https://ubuntu.com/security/CVE-2025-40066 · Vendor Advisory
• https://ubuntu.com/security/CVE-2025-40217 · Vendor Advisory
• https://ubuntu.com/security/CVE-2025-40331 · Vendor Advisory
• https://ubuntu.com/security/CVE-2025-40166 · Vendor Advisory
• https://ubuntu.com/security/CVE-2025-40063 · Vendor Advisory
• https://ubuntu.com/security/CVE-2025-40035 · Vendor Advisory
• https://ubuntu.com/security/CVE-2025-40049 · Vendor Advisory
• https://ubuntu.com/security/CVE-2025-40085 · Vendor Advisory
• https://ubuntu.com/security/CVE-2025-40315 · Vendor Advisory
• https://ubuntu.com/security/CVE-2025-40185 · Vendor Advisory
• https://ubuntu.com/security/CVE-2025-40223 · Vendor Advisory
• https://ubuntu.com/security/CVE-2025-68246 · Vendor Advisory
• https://ubuntu.com/security/CVE-2025-40333 · Vendor Advisory