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National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities

CVE-2025-38709 Detail

Description

In the Linux kernel, the following vulnerability has been resolved: loop: Avoid updating block size under exclusive owner Syzbot came up with a reproducer where a loop device block size is changed underneath a mounted filesystem. This causes a mismatch between the block device block size and the block size stored in the superblock causing confusion in various places such as fs/buffer.c. The particular issue triggered by syzbot was a warning in __getblk_slow() due to requested buffer size not matching block device block size. Fix the problem by getting exclusive hold of the loop device to change its block size. This fails if somebody (such as filesystem) has already an exclusive ownership of the block device and thus prevents modifying the loop device under some exclusive owner which doesn't expect it.


Metrics

 
NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

References to Advisories, Solutions, and Tools

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URL Source(s) Tag(s)
https://git.kernel.org/stable/c/139a000d20f2f38ce34296feddd641d730fe1c08 kernel.org
https://git.kernel.org/stable/c/5d67b30aefeb7a949040bbb1b4e3b84c5d29a624 kernel.org
https://git.kernel.org/stable/c/7e49538288e523427beedd26993d446afef1a6fb kernel.org
https://git.kernel.org/stable/c/b928438cc87c0bf7ae078e4b7b6e14261e84c5c5 kernel.org

Weakness Enumeration

CWE-ID CWE Name Source

Change History

2 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2025-38709
NVD Published Date:
09/04/2025
NVD Last Modified:
09/25/2025
Source:
kernel.org