CVE-2026-90178

What the bug is

pdata->core_data is allocated in init_temp_data() when the first core temp_data of a package is created, but it is only released from destroy_temp_data(), and only in the branch that handles the package temp_data. Package temp_data is created solely when the CPU supports X86_FEATURE_PTS. On a CPU without it, coretemp_cpu_online() never calls coretemp_add_core() with pkg_flag set, so pdata->pkg_data stays NULL. coretemp_cpu_offline() then skips the removal of the package interface, destroy_temp_data() is never called for package data, and the array is still allocated when coretemp_device_remove() frees the platform data that pointed at it. Release the array in coretemp_device_remove(). destroy_temp_data() sets pdata->core_data to NULL when it frees it, so the added kfree() is a no-op on CPUs that do have PTS. Tested on an Intel Core i5-1135G7. The driver was instrumented to log every allocation and release of pdata->core_data, and the PTS check in coretemp_cpu_online() was patched out to emulate a CPU without package thermal support. Without this change the array was allocated and never released, and coretemp_device_remove() still saw a non-NULL pointer. With it the array is released and the pointer accounting balances. On an unmodified build the release still happens via the package temp_data and the added kfree() sees NULL, with no slab warnings over repeated module load and unload cycles.

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/hwmon/coretemp.c

What this is

CORETEMP HARDWARE MONITORING DRIVERMAINTAINERS section matched on drivers/hwmon/coretemp.c · linux-hwmon@vger.kernel.org · Orphan

Kernel module

coretemp

Check it on the machine

grep -wE 'CONFIG_HWMON|CONFIG_SENSORS_CORETEMP' /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.

lsmod | grep -w coretemp

Prints a line if that module is loaded right now, and nothing if it is not. One that is not loaded can still be loaded later by anything that needs it.

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.

• bookwormMnot built on amd64/cloud-amd64, arm64/arm64, arm64/cloud-arm64, arm64/rt/arm64, armhf/armmp, armhf/armmp-lpae, armhf/rt/armmp, ppc64el/powerpc64le
• trixieMnot built on amd64/cloud-amd64, arm64/arm64, arm64/arm64-16k, arm64/cloud-arm64, arm64/rt/arm64, armel/rpi, armhf/armmp, armhf/armmp-lpae, armhf/rt/armmp, ppc64el/powerpc64le, ppc64el/powerpc64le-64k, riscv64/riscv64, s390x/s390x
• forky, sidMnot built on amd64/cloud-amd64, arm64/arm64, arm64/arm64-16k, arm64/cloud-arm64, arm64/rt-arm64, armhf/armmp, armhf/armmp-lpae, loong64/loong64, ppc64el/powerpc64le, ppc64el/powerpc64le-64k, riscv64/riscv64, s390x/s390x
• bookworm · linux-6.12Mnot built on amd64/cloud-amd64, arm64/arm64, arm64/arm64-16k, arm64/cloud-arm64, arm64/rt/arm64, armhf/armmp, armhf/armmp-lpae, armhf/rt/armmp, ppc64el/powerpc64le, ppc64el/powerpc64le-64k

M

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

Build switches

CONFIG_HWMON, CONFIG_SENSORS_CORETEMP

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

0.17%, higher than 5.7% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

unimportantsource

Subsystem

drivers/hwmon

Upstream fixes

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

Introduced	Fixed in	Commit
6.9	6.12.110	dc0d79b1be38
6.9	6.18.52	86c1617b7d4b
6.9	7.2.6	9b23a010a1e8
6.9	7.3	0cd8450c257f

Debian advisories