CVE-2026-92521

What the bug is

acpi_pci_root_add() assigns the freshly allocated root to device->driver_data before dmar_device_add() and pci_acpi_scan_root(). Both failure paths reach the end: label where root is kfree()'d, but only the pci_acpi_scan_root() path clears driver_data first. When dmar_device_add() fails during a hot-add, root is freed while device->driver_data still points at it. The ACPI core does not clear driver_data on attach failure, so a later acpi_pci_find_root() call may dereference this dangling pointer. acpi_pci_root_remove() has the same problem: it frees root without clearing device->driver_data, leaving a dangling pointer behind after the root bridge is removed. Move the NULL assignment to the shared end: label so every error path in acpi_pci_root_add() clears driver_data before freeing root, and clear it in acpi_pci_root_remove() as well, so the object is never left reachable through driver_data after being freed.

Where it lives

The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.

drivers/acpi/pci_root.c

What this is

PCI SUBSYSTEMMAINTAINERS section matched on drivers/acpi/pci* · linux-pci@vger.kernel.org · Supported

Check it on the machine

grep -wE 'CONFIG_ACPI|CONFIG_PCI' /boot/config-$(uname -r)

Reads the booted kernel's own configuration, on the machine and nowhere else. =y is built in, =m is a module, and an is not set line means the code is not there.

Show whether Debian builds this, per release

Debian builds this, but not on every flavour. At least one release below builds the code on some of its kernel flavours and not on others, so the answer depends on the architecture and flavour installed.

• bookwormYnot built on armhf/armmp, armhf/armmp-lpae, armhf/rt/armmp, ppc64el/powerpc64le
• trixieYnot built on armel/rpi, armhf/armmp, armhf/armmp-lpae, armhf/rt/armmp, ppc64el/powerpc64le, ppc64el/powerpc64le-64k, s390x/s390x
• forky, sidYnot built on armhf/armmp, armhf/armmp-lpae, ppc64el/powerpc64le, ppc64el/powerpc64le-64k, s390x/s390x
• bookworm · linux-6.12Ynot built on armhf/armmp, armhf/armmp-lpae, armhf/rt/armmp, ppc64el/powerpc64le, ppc64el/powerpc64le-64k

Y

built in where it is built at all; some flavours do not build it

Build switches

CONFIG_ACPI, CONFIG_PCI

Reads as

all on means the file is compiled; any one off means it is not.

From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS kbuild Makefiles Debian linux-config packages

Signals

Published

2026-09-17 (31 days ago)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

0.18%, higher than 6.8% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

not yet assignedsource

Subsystem

drivers/acpi

Upstream fixes

The versions the CNA records as introducing and fixing this, and the commit for each. source

Introduced	Fixed in	Commit
2.6.28	5.10.270	321bb0eb1486
2.6.28	5.15.221	3c1e8a14f9d0
2.6.28	6.1.188	a285fa3780c7
2.6.28	6.6.157	6aaf6dbf54fd
2.6.28	6.12.110	70cf773cca30
2.6.28	6.18.52	3eee4c21931d
2.6.28	7.2.6	6e11ac626f9f
2.6.28	7.3	8a742141f7ab

Debian advisories