CVE-2025-21853

Medium

In the Linux kernel, the following vulnerability has been resolved: bpf: avoid holding freeze_mutex during mmap operation We use map->freeze_mutex to prevent races between map_freeze() and memory mapping BPF map contents with writable permissions. The way we naively do this means we'll hold freeze_mutex for entire duration of all the mm and VMA manipulations, which is completely unnecessary. This can potentially also lead to deadlocks, as reported by syzbot in [0]. So, instead, hold freeze_mutex only during writeability checks, bump (proactively) "write active" count for the map, unlock the mutex and proceed with mmap logic. And only if something went wrong during mmap logic, then undo that "write active" counter increment. [0] https://lore.kernel.org/bpf/[email protected]/

Package Linux Kernel
Published 2025-03-12
Last modified 2025-11-03
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

5.5

out of 10
Medium
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
High
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected versions

Linux kernel versions 5.5 and later are affected. Fixed in 5.10.237, 5.15.181, 6.1.135, 6.6.80, 6.12.17, 6.13.5, 6.14 and their respective stable series.

Affected from
≥ 5.5
Fixed in
✓ 5.10.237 5.10.x ✓ 5.15.181 5.15.x ✓ 6.1.135 6.1.x ✓ 6.6.80 6.6.x ✓ 6.12.17 6.12.x ✓ 6.13.5 6.13.x ✓ 6.14

References

The following references provide additional information about CVE-2025-21853 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

7 patch commits total View all on NVD

Frequently asked questions

  • What is CVE-2025-21853?

    CVE-2025-21853 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 . It affects Linux kernel versions from 5.5 onward and has been patched in 5.10.237, 5.15.181, 6.1.135 and others. CVE-2025-21853 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2025-21853?

    CVE-2025-21853 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H .

  • Is there a patch available for CVE-2025-21853?

    Yes — CVE-2025-21853 has been patched. Fixed versions include 5.10.237, 5.15.181, 6.1.135 and others. If you are running Linux kernel 5.5 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2025-21853 actively exploited?

    No — CVE-2025-21853 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

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