CVEvulnerability
CVE-2026-90178
- Status
- Received
- Published
- 2026-09-17
- Last modified
- 2026-10-19
- Assigner
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Description
In the Linux kernel, the following vulnerability has been resolved:
hwmon: (coretemp) Fix core_data leak on CPUs without PTS
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.
References
- https://git.kernel.org/stable/c/0cd8450c257faa0cece0e0c43d3b55d1a389acc7 git.kernel.org
- https://git.kernel.org/stable/c/86c1617b7d4b001b20a71deda3c791538a4fa6aa git.kernel.org
- https://git.kernel.org/stable/c/9b23a010a1e8232974617c412cb9f578f3378b70 git.kernel.org
- https://git.kernel.org/stable/c/dc0d79b1be384e7f6a2308356afd10dcf3bf940f git.kernel.org