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Fencer Vulns
high 8.8

CVE-2022-50241 json

NFSD: fix use-after-free on source server when doing inter-server copy

published 2025-09-15 13 mo ago modified 2026-10-15 24 d ago also EUVD-2022-55511

cvss
8.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 31%
public exploits
0
none known

Summary

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

NFSD: fix use-after-free on source server when doing inter-server copy

Use-after-free occurred when the laundromat tried to free expired cpntf_state entry on the s2s_cp_stateids list after inter-server copy completed. The sc_cp_list that the expired copy state was inserted on was already freed.

When COPY completes, the Linux client normally sends LOCKU(lock_state x), FREE_STATEID(lock_state x) and CLOSE(open_state y) to the source server. The nfs4_put_stid call from nfsd4_free_stateid cleans up the copy state from the s2s_cp_stateids list before freeing the lock state's stid.

However, sometimes the CLOSE was sent before the FREE_STATEID request. When this happens, the nfsd4_close_open_stateid call from nfsd4_close frees all lock states on its st_locks list without cleaning up the copy state on the sc_cp_list list. When the time the FREE_STATEID arrives the server returns BAD_STATEID since the lock state was freed. This causes the use-after-free error to occur when the laundromat tries to free the expired cpntf_state.

This patch adds a call to nfs4_free_cpntf_statelist in nfsd4_close_open_stateid to clean up the copy state before calling free_ol_stateid_reaplist to free the lock state's stid on the reaplist.

Patch / fix

  • Linux Linux 5.10.150, 5.15.75, 5.19.17, 6.0.3, 6.1
  • linux Debian 14, Debian 13, Debian 12 6.0.3-1

debian advisories DEBIAN-CVE-2022-50241

  • linux Ubuntu 22.04 LTS 5.15.0-60.66
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1030.34
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1029.36
  • linux-gke Ubuntu 22.04 LTS 5.15.0-1027.32
  • linux-ibm Ubuntu 22.04 LTS 5.15.0-1025.28
  • linux-kvm Ubuntu 22.04 LTS 5.15.0-1028.33
  • linux-azure Ubuntu 22.04 LTS 5.15.0-1033.40
  • linux-gkeop Ubuntu 22.04 LTS 5.15.0-1015.19

ubuntu advisories UBUNTU-CVE-2022-50241

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

  • kernel RHEL 9 5.14.0-284.11.1.el9_2
  • perf RHEL 9 5.14.0-284.11.1.el9_2
  • rtla RHEL 9 5.14.0-284.11.1.el9_2
  • bpftool RHEL 9 7.0.0-284.11.1.el9_2
  • kernel-64k RHEL 9 5.14.0-284.11.1.el9_2
  • kernel-core RHEL 9 5.14.0-284.11.1.el9_2
  • kernel-tools RHEL 9 5.14.0-284.11.1.el9_2
  • python3-perf RHEL 9 5.14.0-284.11.1.el9_2

red hat advisories RHSA-2023:2458

  • kernel-rt SLE Micro 5.5 5.14.21-150500.13.109.1
  • kernel-source-rt SLE Micro 5.5 5.14.21-150500.13.109.1
  • kernel-rt SLE Micro 5.4, SLE Micro 5.3 5.14.21-150400.15.133.1
  • kernel-source-rt SLE Micro 5.4, SLE Micro 5.3 5.14.21-150400.15.133.1
  • kernel-64kb SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS, SLE High Performance Computing 15 SP4-ESPOS 5.14.21-150400.24.179.1
  • kernel-syms SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS +3 more 5.14.21-150400.24.179.1
  • kernel-source SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS +3 more 5.14.21-150400.24.179.1
  • kernel-default SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE Micro 5.4 +7 more 5.14.21-150400.24.179.1

suse advisories SUSE-SU-2025:3761-1SUSE-SU-2025:3716-1SUSE-SU-2025:03628-1SUSE-SU-2025:03615-1

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-2022-50241 updated cvss 6.5

kernel: NFSD: fix use-after-free on source server when doing inter-server copy

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more
    affected: workaround, no fix planned “To mitigate this issue, prevent module nfsd from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.”
  • 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 kernel-rt, kernel-rt-kvm, kernel-rt-core, kernel-rt-modules, kernel-rt-debug-kvm, kernel-rt-debug-core, +12 more
    affected: workaround, no fix available “To mitigate this issue, prevent module nfsd from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.”
  • Red Hat Enterprise Linux AppStream (v. 9) perf 5.14.0-284.11.1.el9_2, rtla 5.14.0-284.11.1.el9_2, kernel-devel-matched 5.14.0-284.11.1.el9_2, kernel-64k-devel-matched 5.14.0-284.11.1.el9_2, kernel-debug-devel-matched 5.14.0-284.11.1.el9_2, kernel-debuginfo-common-s390x 5.14.0-284.11.1.el9_2, +5 more Red Hat Enterprise Linux BaseOS (v. 9) bpftool 7.0.0-284.11.1.el9_2, kernel 5.14.0-284.11.1.el9_2, kernel-64k 5.14.0-284.11.1.el9_2, kernel-core 5.14.0-284.11.1.el9_2, kernel-tools 5.14.0-284.11.1.el9_2, python3-perf 5.14.0-284.11.1.el9_2, +28 more Red Hat Enterprise Linux CRB (v. 9) kernel-debuginfo-common-s390x 5.14.0-284.11.1.el9_2, kernel-debuginfo-common-x86_64 5.14.0-284.11.1.el9_2, kernel-debuginfo-common-aarch64 5.14.0-284.11.1.el9_2, kernel-debuginfo-common-ppc64le 5.14.0-284.11.1.el9_2
    fixed: vendor fix “To mitigate this issue, prevent module nfsd from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2023:2458
  • 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

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
24 d ago

Exploit prediction

0.37% chance of exploitation in the next 30 days, higher than 31% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

  • Linux Linux

Classification

Weakness
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.