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Fencer Vulns
high 7.8

CVE-2023-52983 json

block, bfq: fix uaf for bfqq in bic_set_bfqq()

published 2025-03-27 19 mo ago modified 2026-08-05 3 mo ago also EUVD-2023-59737

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 20%
public exploits
0
none known

Summary

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

block, bfq: fix uaf for bfqq in bic_set_bfqq()

After commit 64dc8c732f5c ("block, bfq: fix possible uaf for 'bfqq->bic'"), bic->bfqq will be accessed in bic_set_bfqq(), however, in some context bic->bfqq will be freed, and bic_set_bfqq() is called with the freed bic->bfqq.

Fix the problem by always freeing bfqq after bic_set_bfqq().

Patch / fix

  • Linux Linux 5.15.93, 6.1, 6.1.11
  • linux Debian 14, Debian 13, Debian 12 6.1.11-1

debian advisories DEBIAN-CVE-2023-52983

  • linux Ubuntu 22.04 LTS 5.15.0-72.79
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1036.40
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1034.42
  • linux-gke Ubuntu 22.04 LTS 5.15.0-1033.38
  • linux-ibm Ubuntu 22.04 LTS 5.15.0-1030.33
  • linux-kvm Ubuntu 22.04 LTS 5.15.0-1033.38
  • linux-azure Ubuntu 22.04 LTS 5.15.0-1038.45
  • linux-gkeop Ubuntu 22.04 LTS 5.15.0-1020.25

ubuntu advisories UBUNTU-CVE-2023-52983

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-rt SLE Micro 5.2 5.3.18-150300.235.1
  • kernel-source-rt SLE Micro 5.2 5.3.18-150300.235.1
  • kernel-default SLE Micro 5.2 5.3.18-150300.59.235.1
  • kernel-default-base SLE Micro 5.2 5.3.18-150300.59.235.1.150300.18.140.1
  • kernel-64kb SLES 15 SP5-LTSS, SLE High Performance Computing 15 SP5-LTSS, SLE High Performance Computing 15 SP5-ESPOS 5.14.21-150500.55.100.1
  • kernel-syms SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE High Performance Computing 15 SP5-LTSS +1 more 5.14.21-150500.55.100.1
  • kernel-source SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE Micro 5.5 +2 more 5.14.21-150500.55.100.1
  • kernel-default SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE Micro 5.5 +3 more 5.14.21-150500.55.100.1

suse advisories SUSE-SU-2026:0495-1SUSE-SU-2026:0475-1SUSE-SU-2025:1241-1SUSE-SU-2025:1195-1SUSE-SU-2025:1183-1SUSE-SU-2025:1176-1

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-2023-52983 updated cvss 7.0

kernel: block, bfq: fix uaf for bfqq in bic_set_bfqq()

  • Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more
    affected: workaround, no fix planned “To mitigate this issue, prevent module bfq 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 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more
    affected: workaround, no fix available “To mitigate this issue, prevent module bfq 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 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 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
19 mo ago

Exploit prediction

0.28% chance of exploitation in the next 30 days, higher than 20% 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
CISA ADP 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.