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Fencer Vulns
medium 4.7

CVE-2025-38567 json

nfsd: avoid ref leak in nfsd_open_local_fh()

published 2025-08-19 14 mo ago modified 2026-06-17 4 mo ago also EUVD-2025-27906

cvss
4.7
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.1%
EPSS 0.1% chance of exploitation in 30 days, percentile 1%
public exploits
0
none known

Summary

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

nfsd: avoid ref leak in nfsd_open_local_fh()

If two calls to nfsd_open_local_fh() race and both successfully call nfsd_file_acquire_local(), they will both get an extra reference to the net to accompany the file reference stored in *pnf.

One of them will fail to store (using xchg()) the file reference in *pnf and will drop that reference but WON'T drop the accompanying reference to the net. This leak means that when the nfs server is shut down it will hang in nfsd_shutdown_net() waiting for &nn->nfsd_net_free_done.

This patch adds the missing nfsd_net_put().

Patch / fix

  • Linux Linux 6.15.10, 6.16.1, 6.17
  • linux-aws-6.14 Ubuntu 24.04 LTS 6.14.0-1017.17~24.04.1
  • linux-gcp-6.14 Ubuntu 24.04 LTS 6.14.0-1020.21~24.04.1
  • linux-oem-6.14 Ubuntu 24.04 LTS 6.14.0-1016.16
  • linux-azure-6.14 Ubuntu 24.04 LTS 6.14.0-1017.17~24.04.1
  • linux-riscv-6.14 Ubuntu 24.04 LTS 6.14.0-36.36.1~24.04.1
  • linux-oracle-6.14 Ubuntu 24.04 LTS 6.14.0-1017.17~24.04.1
  • linux-realtime-6.14 Ubuntu Pro Realtime 24.04 LTS 6.14.0-1016.16~24.04.1

ubuntu advisories UBUNTU-CVE-2025-38567

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2025-38567 updated

kernel: nfsd: avoid ref leak in nfsd_open_local_fh()

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more Red Hat Enterprise Linux 10 kernel
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.12% chance of exploitation in the next 30 days, higher than 1% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 4.7 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Linux Linux

Classification

Weakness
  • CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.