CVE-2025-21795: NFSD: fix hang in nfsd4_shutdown_callback

Published Feb 27, 2025
·
Updated

In the Linux kernel, the following vulnerability has been resolved:

NFSD: fix hang in nfsd4shutdowncallback

If nfs4client is in courtesy state then there is no point to send the callback. This causes nfsd4shutdowncallback to hang since clcbinflight is not 0. This hang lasts about 15 minutes until TCP notifies NFSD that the connection was dropped.

This patch modifies nfsd4runcbwork to skip the RPC call if nfs4client is in courtesy state.

Affected Software

13 affected components
Linux Linux kernel
Linux Linux kernel>=5.10.220<5.10.235
Linux Linux kernel>=5.15.154<5.15.179
Linux Linux kernel>=5.19<6.1.129
Linux Linux kernel>=6.2<6.6.79
Linux Linux kernel>=6.7<6.12.16
Linux Linux kernel>=6.13<6.13.4
Linux Linux kernel=6.14-rc1
Linux Linux kernel=6.14-rc2
IBM Verify Identity Access<=11.0 - 11.0.2
IBM Security Verify Access<=10.0 - 10.0.9.1
IBM Verify Identity Access Container<=11.0 - 11.0.2
IBM Security Verify Access Container<=10.0 - 10.0.9.1

Event History

Feb 27, 2025
CVE Published
via MITRE·02:18 AM
Data Sourced
via MITRE·02:18 AM
Description
Data Sourced
via Red Hat·03:01 AM
DescriptionSeverityAffected Software
Data Sourced
via NVD·03:15 AM
RemedyDescriptionSeverityAffected Software
Jul 8, 2026
Data Sourced
via IBM·12:00 AM
DescriptionAffected Software

Parent advisories

This vulnerability appears in the following advisories.

Free Weekly Intel

Don't miss critical vulnerabilities

Join thousands of security professionals who receive our weekly digest of trending CVEs, zero-days, and exploited vulnerabilities.

No spam. Unsubscribe anytime.

Frequently Asked Questions

1

What is the severity of CVE-2025-21795?

The severity of CVE-2025-21795 is moderate due to its potential to cause service disruption.

2

How do I fix CVE-2025-21795?

To fix CVE-2025-21795, you should update your Linux kernel to the latest stable version that includes the patch.

3

What systems are affected by CVE-2025-21795?

CVE-2025-21795 affects various versions of the Linux kernel.

4

What does CVE-2025-21795 impact?

CVE-2025-21795 impacts the NFS daemon, which can lead to a hang during shutdown if in a specific state.

5

When was CVE-2025-21795 disclosed?

CVE-2025-21795 was disclosed in early 2025.

Contact

SecAlerts Pty Ltd.
132 Wickham Terrace
Fortitude Valley,
QLD 4006, Australia
info@secalerts.co
By using SecAlerts services, you agree to our services end-user license agreement. This website is safeguarded by reCAPTCHA and governed by the Google Privacy Policy and Terms of Service. All names, logos, and brands of products are owned by their respective owners, and any usage of these names, logos, and brands for identification purposes only does not imply endorsement. If you possess any content that requires removal, please get in touch with us.
© 2026 SecAlerts Pty Ltd.
ABN: 70 645 966 203, ACN: 645 966 203
CVE-2025-21795 - NFSD: fix hang in nfsd4_shutdown_callback - SecAlerts