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Fencer Vulns
no cvss —

CVE-2023-54038 json

Bluetooth: hci_conn: return ERR_PTR instead of NULL when there is no link

published 2025-12-24 10 mo ago modified 2026-06-17 4 mo ago also EUVD-2025-205124

cvss
—
not scored
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 7%
public exploits
0
none known

Summary

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

Bluetooth: hci_conn: return ERR_PTR instead of NULL when there is no link

hci_connect_sco currently returns NULL when there is no link (i.e. when hci_conn_link() returns NULL).

sco_connect() expects an ERR_PTR in case of any error (see line 266 in sco.c). Thus, hcon set as NULL passes through to sco_conn_add(), which tries to get hcon->hdev, resulting in dereferencing a NULL pointer as reported by syzkaller.

The same issue exists for iso_connect_cis() calling hci_connect_cis().

Thus, make hci_connect_sco() and hci_connect_cis() return ERR_PTR instead of NULL.

Patch / fix

  • Linux Linux 6.4, 6.4.7, 6.5
  • linux Debian 14, Debian 13 6.4.11-1

debian advisories DEBIAN-CVE-2023-54038

  • kernel RHEL 9 5.14.0-427.13.1.el9_4
  • rv RHEL 9 5.14.0-427.13.1.el9_4
  • perf RHEL 9 5.14.0-427.13.1.el9_4
  • rtla RHEL 9 5.14.0-427.13.1.el9_4
  • bpftool RHEL 9 7.3.0-427.13.1.el9_4
  • libperf RHEL 9 5.14.0-427.13.1.el9_4
  • kernel-rt RHEL 9 5.14.0-427.13.1.el9_4
  • kernel-64k RHEL 9 5.14.0-427.13.1.el9_4

red hat advisories RHSA-2024:2394

  • kernel-rt Linux Micro 6.1, Linux Micro 6.0 6.4.0-40.1
  • kernel-source-rt Linux Micro 6.1, Linux Micro 6.0 6.4.0-40.1
  • kernel-source Linux Micro 6.1, Linux Micro 6.0 6.4.0-39.1
  • kernel-default Linux Micro 6.1, Linux Micro 6.0 6.4.0-39.1
  • kernel-kvmsmall Linux Micro 6.1, Linux Micro 6.0 6.4.0-39.1
  • kernel-default-base Linux Micro 6.1, Linux Micro 6.0 6.4.0-39.1.21.16
  • kernel-64kb SLE Module for Basesystem 15 SP7 6.4.0-150700.53.28.1
  • kernel-syms SLE Module for Development Tools 15 SP7 6.4.0-150700.53.28.1

suse advisories SUSE-SU-2026:20845-1SUSE-SU-2026:20876-1SUSE-SU-2026:20477-1SUSE-SU-2026:20498-1SUSE-SU-2026:0315-1SUSE-SU-2026:0293-1

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-2023-54038 updated cvss 5.5

kernel: Linux kernel: Denial of Service in Bluetooth HCI connection handling

  • 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 “Fix deferred”
  • Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-427.13.1.el9_4, perf 5.14.0-427.13.1.el9_4, rtla 5.14.0-427.13.1.el9_4, kernel-devel-matched 5.14.0-427.13.1.el9_4, kernel-64k-devel-matched 5.14.0-427.13.1.el9_4, kernel-debug-devel-matched 5.14.0-427.13.1.el9_4, +6 more Red Hat Enterprise Linux BaseOS (v. 9) bpftool 7.3.0-427.13.1.el9_4, kernel 5.14.0-427.13.1.el9_4, kernel-64k 5.14.0-427.13.1.el9_4, kernel-core 5.14.0-427.13.1.el9_4, kernel-tools 5.14.0-427.13.1.el9_4, python3-perf 5.14.0-427.13.1.el9_4, +28 more Red Hat Enterprise Linux CRB (v. 9) libperf 5.14.0-427.13.1.el9_4, kernel-debuginfo-common-s390x 5.14.0-427.13.1.el9_4, kernel-debuginfo-common-x86_64 5.14.0-427.13.1.el9_4, kernel-debuginfo-common-aarch64 5.14.0-427.13.1.el9_4, kernel-debuginfo-common-ppc64le 5.14.0-427.13.1.el9_4 Red Hat Enterprise Linux NFV (v. 9) kernel-rt 5.14.0-427.13.1.el9_4, kernel-rt-kvm 5.14.0-427.13.1.el9_4, kernel-rt-core 5.14.0-427.13.1.el9_4, kernel-rt-modules 5.14.0-427.13.1.el9_4, kernel-rt-debug-kvm 5.14.0-427.13.1.el9_4, kernel-rt-debug-core 5.14.0-427.13.1.el9_4, +6 more Red Hat Enterprise Linux RT (v. 9) kernel-rt 5.14.0-427.13.1.el9_4, kernel-rt-core 5.14.0-427.13.1.el9_4, kernel-rt-modules 5.14.0-427.13.1.el9_4, kernel-rt-debug-core 5.14.0-427.13.1.el9_4, kernel-rt-modules-core 5.14.0-427.13.1.el9_4, kernel-rt-debug-modules 5.14.0-427.13.1.el9_4, +4 more
    fixed: vendor fix RHSA-2024:2394
  • 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 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

0.18% chance of exploitation in the next 30 days, higher than 7% of all scored CVEs (FIRST EPSS, 2026-11-08).

Affected products

  • Linux Linux

Classification

Technology feeds

References

Sources

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