CVE-2026-53278

What the bug is

__destroy_component_cfg() is called to free the configuration array. It uses the embedded 'garbage' structure, which means the array has to be allocated. If __destroy_component_cfg() is called from mpam_disable() before the configuration was ever allocated, then a NULL pointer is dereferenced. Check for this case and return early if the configuration is not allocated. __destroy_component_cfg() also frees the mbwu_state as this is allocated by __allocate_component_cfg(). As the mbwu_state is allocated after comp->cfg is set, and is also under mpam_list_lock, only the first pointer needs checking.

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/resctrl/mpam_devices.c

What this is

MPAM DRIVERMAINTAINERS section matched on drivers/resctrl/mpam_* · Maintained

Check it on the machine

grep -w CONFIG_ARM64_MPAM_DRIVER /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. The build rule could not be established for 2 releases, so nothing is claimed about those.

• bookworm, trixie?
• forky, sidYnot built on amd64/amd64, amd64/cloud-amd64, amd64/rt-amd64, armhf/armmp, armhf/armmp-lpae, loong64/loong64, ppc64el/powerpc64le, ppc64el/powerpc64le-64k, riscv64/riscv64, s390x/s390x

?

not established - no Makefile entry for the affected file

Y

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

Where a release above reads "not established", no build rule for the affected file was found in that release's kernel tree. That is a gap in this lookup, not a finding that the code is absent.

Build switch

CONFIG_ARM64_MPAM_DRIVER

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

2026-06-26 (4 months ago)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

0.14%, higher than 3.2% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

unimportantsource

Subsystem

drivers/resctrl

Upstream fixes

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

Introduced	Fixed in	Commit
6.19	7.0.10	8eb6dc76eeae
6.19	7.1	6ccbb613b42a