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Fencer Vulns
high 7.8

CVE-2022-49995 json

writeback: avoid use-after-free after removing device

published 2025-06-18 16 mo ago modified 2026-08-05 3 mo ago also EUVD-2022-55274

cvss
7.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 17%
public exploits
0
none known

Summary

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

writeback: avoid use-after-free after removing device

When a disk is removed, bdi_unregister gets called to stop further writeback and wait for associated delayed work to complete. However, wb_inode_writeback_end() may schedule bandwidth estimation dwork after this has completed, which can result in the timer attempting to access the just freed bdi_writeback.

Fix this by checking if the bdi_writeback is alive, similar to when scheduling writeback work.

Since this requires wb->work_lock, and wb_inode_writeback_end() may get called from interrupt, switch wb->work_lock to an irqsafe lock.

Patch / fix

  • Linux Linux 5.15.64, 5.19.6, 6.0
  • linux Debian 14, Debian 13, Debian 12 6.0.2-1

debian advisories DEBIAN-CVE-2022-49995

  • linux Ubuntu 22.04 LTS 5.15.0-53.59
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1023.27
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1022.29
  • linux-gke Ubuntu 22.04 LTS 5.15.0-1020.25
  • linux-ibm Ubuntu 22.04 LTS 5.15.0-1018.21
  • linux-kvm Ubuntu 22.04 LTS 5.15.0-1021.26
  • linux-azure Ubuntu 22.04 LTS 5.15.0-1023.29
  • linux-gkeop Ubuntu 22.04 LTS 5.15.0-1008.12

ubuntu advisories UBUNTU-CVE-2022-49995

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 8 4.18.0-513.5.1.el8_9
  • perf RHEL 8 4.18.0-513.5.1.el8_9
  • bpftool RHEL 8 4.18.0-513.5.1.el8_9
  • kernel-core RHEL 8 4.18.0-513.5.1.el8_9
  • kernel-tools RHEL 8 4.18.0-513.5.1.el8_9
  • python3-perf RHEL 8 4.18.0-513.5.1.el8_9
  • kernel-modules RHEL 8 4.18.0-513.5.1.el8_9
  • kernel-zfcpdump RHEL 8 4.18.0-513.5.1.el8_9

red hat advisories RHSA-2025:12526RHSA-2025:12525RHSA-2023:7077RHSA-2023:2458RHSA-2024:0575

  • kernel-64kb SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS, SLE High Performance Computing 15 SP4-ESPOS 5.14.21-150400.24.170.2
  • kernel-syms SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS +3 more 5.14.21-150400.24.170.1
  • kernel-source SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS +3 more 5.14.21-150400.24.170.1
  • kernel-default SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE Micro 5.4 +6 more 5.14.21-150400.24.170.2
  • kernel-zfcpdump SLES 15 SP4-LTSS, Manager Server 4.3 5.14.21-150400.24.170.2
  • kernel-obs-build SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS +1 more 5.14.21-150400.24.170.2
  • kernel-default-base SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE Micro 5.4 +5 more 5.14.21-150400.24.170.2.150400.24.86.2
  • kernel-rt SLE Micro 5.4, SLE Micro 5.3 5.14.21-150400.15.124.1

suse advisories SUSE-SU-2025:02537-1SUSE-SU-2025:02322-1SUSE-SU-2025:02321-1SUSE-SU-2025:02264-1

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-2022-49995 updated cvss 7.0

kernel: writeback: avoid use-after-free after removing device

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more
    affected: no fix planned “Out of support scope”
  • 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: no fix available
  • Red Hat CodeReady Linux Builder (v. 8) kernel-debuginfo-common-x86_64 4.18.0-513.5.1.el8_9, kernel-debuginfo-common-aarch64 4.18.0-513.5.1.el8_9, kernel-debuginfo-common-ppc64le 4.18.0-513.5.1.el8_9
    fixed: vendor fix RHSA-2023:7077
  • Red Hat CodeReady Linux Builder EUS (v.8.8) kernel-debuginfo-common-x86_64 4.18.0-477.43.1.el8_8, kernel-debuginfo-common-aarch64 4.18.0-477.43.1.el8_8, kernel-debuginfo-common-ppc64le 4.18.0-477.43.1.el8_8
    fixed: vendor fix RHSA-2024:0575
  • 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
    fixed: vendor fix RHSA-2023:2458
  • Red Hat Enterprise Linux AppStream E4S (v.9.0) perf 5.14.0-70.140.1.el9_0, kernel-devel-matched 5.14.0-70.140.1.el9_0, kernel-debug-devel-matched 5.14.0-70.140.1.el9_0, kernel-debuginfo-common-s390x 5.14.0-70.140.1.el9_0, kernel-zfcpdump-devel-matched 5.14.0-70.140.1.el9_0, kernel-debuginfo-common-x86_64 5.14.0-70.140.1.el9_0, +2 more
    fixed: vendor fix RHSA-2025:12526
  • Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-513.5.1.el8_9, kernel 4.18.0-513.5.1.el8_9, bpftool 4.18.0-513.5.1.el8_9, kernel-core 4.18.0-513.5.1.el8_9, kernel-tools 4.18.0-513.5.1.el8_9, python3-perf 4.18.0-513.5.1.el8_9, +15 more
    fixed: vendor fix RHSA-2023:7077
  • 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
    fixed: vendor fix RHSA-2023:2458
show 5 more
  • Red Hat Enterprise Linux BaseOS E4S (v.9.0) kernel 5.14.0-70.140.1.el9_0, bpftool 5.14.0-70.140.1.el9_0, kernel-core 5.14.0-70.140.1.el9_0, kernel-tools 5.14.0-70.140.1.el9_0, python3-perf 5.14.0-70.140.1.el9_0, kernel-modules 5.14.0-70.140.1.el9_0, +14 more
    fixed: vendor fix RHSA-2025:12526
  • Red Hat Enterprise Linux BaseOS EUS (v.8.8) perf 4.18.0-477.43.1.el8_8, kernel 4.18.0-477.43.1.el8_8, bpftool 4.18.0-477.43.1.el8_8, kernel-core 4.18.0-477.43.1.el8_8, kernel-tools 4.18.0-477.43.1.el8_8, python3-perf 4.18.0-477.43.1.el8_8, +15 more
    fixed: vendor fix RHSA-2024:0575
  • 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 RHSA-2023:2458
  • Red Hat Enterprise Linux NFV E4S (v.9.0) kernel-rt 5.14.0-70.140.1.rt21.212.el9_0, kernel-rt-kvm 5.14.0-70.140.1.rt21.212.el9_0, kernel-rt-core 5.14.0-70.140.1.rt21.212.el9_0, kernel-rt-modules 5.14.0-70.140.1.rt21.212.el9_0, kernel-rt-debug-kvm 5.14.0-70.140.1.rt21.212.el9_0, kernel-rt-debug-core 5.14.0-70.140.1.rt21.212.el9_0, +4 more Red Hat Enterprise Linux Real Time E4S (v.9.0) kernel-rt 5.14.0-70.140.1.rt21.212.el9_0, kernel-rt-core 5.14.0-70.140.1.rt21.212.el9_0, kernel-rt-modules 5.14.0-70.140.1.rt21.212.el9_0, kernel-rt-debug-core 5.14.0-70.140.1.rt21.212.el9_0, kernel-rt-debug-modules 5.14.0-70.140.1.rt21.212.el9_0, kernel-rt-modules-extra 5.14.0-70.140.1.rt21.212.el9_0, +2 more
    fixed: vendor fix RHSA-2025:12525
  • Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 kernel-rt, kernel-rt-kvm, kernel-rt-core, kernel-rt-modules, kernel-rt-debug-kvm, kernel-rt-debug-core, +6 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

0.26% chance of exploitation in the next 30 days, higher than 17% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.8 CVSS:3.1/AV:L/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.