RHSA-2023:4531HighCVSS 8.1

Red Hat Security Advisory: kpatch-patch security update

Published
August 8, 2023
Last Modified
July 30, 2026

🔗 CVE IDs covered (3)

CVE-2022-42896 →CVE-2023-1281 →CVE-2023-1829 →

📋 Description

CVE-2022-42896 — kernel: use-after-free in l2cap_connect and l2cap_le_connect_req in net/bluetooth/l2cap_core.c CVE-2023-1281 — kernel: tcindex: use-after-free vulnerability in traffic control index filter allows privilege escalation CVE-2023-1829 — kernel: Use-after-free vulnerability in the Linux Kernel traffic control index filter

🎯 Affected products22

  • Red Hat Enterprise Linux BaseOS (v. 8)
  • kpatch-patch-4_18_0-477_10_1-0:1-2.el8_8.ppc64le as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • kpatch-patch-4_18_0-477_10_1-0:1-2.el8_8.src as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • kpatch-patch-4_18_0-477_10_1-0:1-2.el8_8.x86_64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • kpatch-patch-4_18_0-477_10_1-debuginfo-0:1-2.el8_8.ppc64le as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • kpatch-patch-4_18_0-477_10_1-debuginfo-0:1-2.el8_8.x86_64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • kpatch-patch-4_18_0-477_10_1-debugsource-0:1-2.el8_8.ppc64le as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • kpatch-patch-4_18_0-477_10_1-debugsource-0:1-2.el8_8.x86_64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • kpatch-patch-4_18_0-477_13_1-0:1-1.el8_8.ppc64le as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • kpatch-patch-4_18_0-477_13_1-0:1-1.el8_8.src as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • kpatch-patch-4_18_0-477_13_1-0:1-1.el8_8.x86_64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • kpatch-patch-4_18_0-477_13_1-debuginfo-0:1-1.el8_8.ppc64le as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • kpatch-patch-4_18_0-477_13_1-debuginfo-0:1-1.el8_8.x86_64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • kpatch-patch-4_18_0-477_13_1-debugsource-0:1-1.el8_8.ppc64le as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • kpatch-patch-4_18_0-477_13_1-debugsource-0:1-1.el8_8.x86_64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • kpatch-patch-4_18_0-477_15_1-0:1-1.el8_8.ppc64le as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • kpatch-patch-4_18_0-477_15_1-0:1-1.el8_8.src as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • kpatch-patch-4_18_0-477_15_1-0:1-1.el8_8.x86_64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • kpatch-patch-4_18_0-477_15_1-debuginfo-0:1-1.el8_8.ppc64le as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • kpatch-patch-4_18_0-477_15_1-debuginfo-0:1-1.el8_8.x86_64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • kpatch-patch-4_18_0-477_15_1-debugsource-0:1-1.el8_8.ppc64le as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • kpatch-patch-4_18_0-477_15_1-debugsource-0:1-1.el8_8.x86_64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)

✅ Remediation

For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Workaround: This flaw can be mitigated by disabling Bluetooth on the operating system level. The kernel modules can be prevented from being loaded by using system-wide modprobe rules. For instructions on how to disable Bluetooth on RHEL please refer to https://access.redhat.com/solutions/2682931. Alternatively Bluetooth can be disabled within the hardware or at BIOS level which will also provide an effective mitigation as the kernel will not be able to detect that Bluetooth hardware is present on the system. Workaround: This flaw can be mitigated by preventing the affected traffic control index filter (cls_tcindex) kernel module from loading during the boot time, ensure the module is added into the blacklist file. ~~~ Refer: How do I blacklist a kernel module to prevent it from loading automatically? https://access.redhat.com/solutions/41278 ~~~ Workaround: To mitigate this issue, prevent the module cls_tcindex from being loaded. Please see https://access.redhat.com/solutions/41278 on how to blacklist a kernel module to prevent it from loading automatically.

🔗 References (6)