🛡️ CVE-2025-21832 on Debian — linux

⚪ Unknown ✅ No Known Exploit OSV

N/A

CVSS Score

0 Low4 Medium7 High9 Critical10

Description

In the Linux kernel, the following vulnerability has been resolved: block: don't revert iter for -EIOCBQUEUED blkdev_read_iter() has a few odd checks, like gating the position and count adjustment on whether or not the result is bigger-than-or-equal to zero (where bigger than makes more sense), and not checking the return value of blkdev_direct_IO() before doing an iov_iter_revert(). The latter can lead to attempting to revert with a negative value, which when passed to iov_iter_revert() as an unsigned value will lead to throwing a WARN_ON() because unroll is bigger than MAX_RW_COUNT. Be sane and don't revert for -EIOCBQUEUED, like what is done in other spots.

Distribution advisory

This page covers CVE-2025-21832 as tracked by Debian, for the package linux. The fix is available in version 6.12.15-1; earlier versions remain affected.

How this vulnerability can be exploited

This issue can be reached with local access to the system, attack complexity is low, an attacker needs low-level privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality none, integrity none, availability high.

Affected software

DEBIAN-CVE-2025-21832 is recorded against 2 packages.

linux (fixed in 6.12.15-1)
linux-6.1 (fixed in 6.1.129-1~deb11u1)

Timeline and source

Published on 6 March 2025 and last revised on 4 August 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.

References

security-tracker.debian.org (Advisory)

CVE-2025-21832 on other distributions

Each distribution ships its own build and its own fixed version. Pick the one you run:

BellSoft Base record Ubuntu 22.04 (Root.io)Ubuntu 24.04 (Root.io)Ubuntu

Details

Severity Unknown

CVSS Score N/A

CVSS Vector CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CWE N/A

Public Exploit ✅ No

Source OSV

Published 2025-03-06

Updated 2026-08-20

Modified 2026-08-04

Fix URL N/A

Affected Packages

Software	From version	Fixed in
linux	—	6.12.15-1
linux-6.1	—	6.1.129-1~deb11u1

References

ADVISORY https://security-tracker.debian.org/tracker/CVE-2025-21832

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