BaseFortify

Publication date: 2025-11-12

Last updated on: 2025-11-14

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: ext4: avoid potential buffer over-read in parse_apply_sb_mount_options() Unlike other strings in the ext4 superblock, we rely on tune2fs to make sure s_mount_opts is NUL terminated. Harden parse_apply_sb_mount_options() by treating s_mount_opts as a potential __nonstring.

CVSS Scores

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Meta Information

Published

2025-11-12

Last Modified

2025-11-14

Generated

2026-07-06

AI Q&A

2025-11-13

EPSS Evaluated

2026-07-05

NVD

CVE-2025-40198

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	*

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-UNKNOWN

Attack-Flow Graph

Executive Summary

This vulnerability is a potential buffer over-read in the Linux kernel's ext4 filesystem code, specifically in the function parse_apply_sb_mount_options(). The issue arises because the code assumes that the s_mount_opts string in the ext4 superblock is NUL terminated, relying on the tune2fs tool to ensure this. However, if s_mount_opts is not properly NUL terminated, it can lead to reading beyond the intended buffer, which is a security risk. The fix hardens the function by treating s_mount_opts as a potential non-string to avoid this over-read.

Impact Analysis

This vulnerability can lead to a buffer over-read, which may cause the system to read memory beyond the intended buffer. This can potentially result in information disclosure, system instability, or crashes. In some cases, such vulnerabilities can be exploited to escalate privileges or execute arbitrary code, depending on the context and how the over-read is leveraged.

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