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Fencer Vulns
high 7.0

CVE-2023-54095 json

powerpc/iommu: Fix notifiers being shared by PCI and VIO buses

published 2025-12-24 10 mo ago modified 2026-10-15 24 d ago also EUVD-2023-60350

cvss
7.0
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 5%
public exploits
0
none known

Summary

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

powerpc/iommu: Fix notifiers being shared by PCI and VIO buses

fail_iommu_setup() registers the fail_iommu_bus_notifier struct to both PCI and VIO buses. struct notifier_block is a linked list node, so this causes any notifiers later registered to either bus type to also be registered to the other since they share the same node.

This causes issues in (at least) the vgaarb code, which registers a notifier for PCI buses. pci_notify() ends up being called on a vio device, converted with to_pci_dev() even though it's not a PCI device, and finally makes a bad access in vga_arbiter_add_pci_device() as discovered with KASAN:

BUG: KASAN: slab-out-of-bounds in vga_arbiter_add_pci_device+0x60/0xe00 Read of size 4 at addr c000000264c26fdc by task swapper/0/1

Call Trace: dump_stack_lvl+0x1bc/0x2b8 (unreliable) print_report+0x3f4/0xc60 kasan_report+0x244/0x698 __asan_load4+0xe8/0x250 vga_arbiter_add_pci_device+0x60/0xe00 pci_notify+0x88/0x444 notifier_call_chain+0x104/0x320 blocking_notifier_call_chain+0xa0/0x140 device_add+0xac8/0x1d30 device_register+0x58/0x80 vio_register_device_node+0x9ac/0xce0 vio_bus_scan_register_devices+0xc4/0x13c __machine_initcall_pseries_vio_device_init+0x94/0xf0 do_one_initcall+0x12c/0xaa8 kernel_init_freeable+0xa48/0xba8 kernel_init+0x64/0x400 ret_from_kernel_thread+0x5c/0x64

Fix this by creating separate notifier_block structs for each bus type.

[mpe: Add #ifdef to fix CONFIG_IBMVIO=n build]

Patch / fix

  • Linux Linux 4.14.326, 4.19.295, 5.4.257, 5.10.195, 5.15.132, 6.1.53, 6.4.16, 6.5.3, 6.6
  • linux Debian 12 6.1.55-1
  • linux Debian 14, Debian 13 6.5.3-1

debian advisories DEBIAN-CVE-2023-54095

  • linux Ubuntu 20.04 LTS 5.4.0-169.187
  • linux Ubuntu 22.04 LTS 5.15.0-94.104
  • linux-aws Ubuntu 20.04 LTS 5.4.0-1116.126
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1053.58
  • linux-gcp Ubuntu 20.04 LTS 5.4.0-1120.129
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1051.59
  • linux-gke Ubuntu 22.04 LTS 5.15.0-1050.55
  • linux-ibm Ubuntu 20.04 LTS 5.4.0-1063.68

ubuntu advisories UBUNTU-CVE-2023-54095

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 5.14.0-503.11.1.el9_5
  • rv RHEL 9 5.14.0-503.11.1.el9_5
  • perf RHEL 9 5.14.0-503.11.1.el9_5
  • rtla RHEL 9 5.14.0-503.11.1.el9_5
  • bpftool RHEL 9 7.4.0-503.11.1.el9_5
  • libperf RHEL 9 5.14.0-503.11.1.el9_5
  • kernel-rt RHEL 9 5.14.0-503.11.1.el9_5
  • kernel-64k RHEL 9 5.14.0-503.11.1.el9_5

red hat advisories RHSA-2024:9315

  • 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-64kb SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS, SLE High Performance Computing 15 SP4-ESPOS 5.14.21-150400.24.194.1
  • kernel-syms SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS +1 more 5.14.21-150400.24.194.1
  • kernel-source SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS +1 more 5.14.21-150400.24.194.1
  • kernel-default SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE Micro 5.4 +5 more 5.14.21-150400.24.194.1
  • kernel-obs-build SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS +1 more 5.14.21-150400.24.194.1
  • kernel-default-base SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE Micro 5.4 +3 more 5.14.21-150400.24.194.1.150400.24.98.3

suse advisories SUSE-SU-2026:20845-1SUSE-SU-2026:20876-1SUSE-SU-2026:0617-1SUSE-SU-2026:20477-1SUSE-SU-2026:20498-1SUSE-SU-2026:0411-1

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-2023-54095 updated cvss 5.5

kernel: powerpc/iommu: Fix notifiers being shared by PCI and VIO buses

  • 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 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: no fix available “Fix deferred”
  • Red Hat CodeReady Linux Builder (v. 9) libperf 5.14.0-503.11.1.el9_5, kernel-debuginfo-common-s390x 5.14.0-503.11.1.el9_5, kernel-debuginfo-common-x86_64 5.14.0-503.11.1.el9_5, kernel-debuginfo-common-aarch64 5.14.0-503.11.1.el9_5, kernel-debuginfo-common-ppc64le 5.14.0-503.11.1.el9_5 Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-503.11.1.el9_5, perf 5.14.0-503.11.1.el9_5, rtla 5.14.0-503.11.1.el9_5, kernel-devel-matched 5.14.0-503.11.1.el9_5, kernel-64k-devel-matched 5.14.0-503.11.1.el9_5, kernel-debug-devel-matched 5.14.0-503.11.1.el9_5, +6 more Red Hat Enterprise Linux BaseOS (v. 9) bpftool 7.4.0-503.11.1.el9_5, kernel 5.14.0-503.11.1.el9_5, kernel-64k 5.14.0-503.11.1.el9_5, kernel-core 5.14.0-503.11.1.el9_5, kernel-tools 5.14.0-503.11.1.el9_5, python3-perf 5.14.0-503.11.1.el9_5, +29 more Red Hat Enterprise Linux Real Time (v. 9) kernel-rt 5.14.0-503.11.1.el9_5, kernel-rt-core 5.14.0-503.11.1.el9_5, kernel-rt-modules 5.14.0-503.11.1.el9_5, kernel-rt-debug-core 5.14.0-503.11.1.el9_5, kernel-rt-modules-core 5.14.0-503.11.1.el9_5, kernel-rt-debug-modules 5.14.0-503.11.1.el9_5, +4 more Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt 5.14.0-503.11.1.el9_5, kernel-rt-kvm 5.14.0-503.11.1.el9_5, kernel-rt-core 5.14.0-503.11.1.el9_5, kernel-rt-modules 5.14.0-503.11.1.el9_5, kernel-rt-debug-kvm 5.14.0-503.11.1.el9_5, kernel-rt-debug-core 5.14.0-503.11.1.el9_5, +6 more
    fixed: vendor fix RHSA-2024:9315
  • Red Hat CodeReady Linux Builder (v. 9) kernel-cross-headers 5.14.0-503.11.1.el9_5 Red Hat Enterprise Linux 10 kernel Red Hat Enterprise Linux AppStream (v. 9) kernel-headers 5.14.0-503.11.1.el9_5
    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

0.16% chance of exploitation in the next 30 days, higher than 5% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.0 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

  • Linux Linux

Classification

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.