CVE-2026-97905

cpufreq: zero-initialize policy cpumask before sysfs publication

N/A
Published: September 25, 2026 at 10:22 AM UTC
Updated: October 19, 2026 at 10:17 AM UTC
1 product affected across 1 vendorLinux Kernel

Using Linux by Linux?

Get instant alerts when new vulnerabilities affect Linux - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Severity
N/A
Exploit prediction
EPSS 0.2%

Description

In the Linux kernel, the following vulnerability has been resolved: cpufreq: zero-initialize policy cpumask before sysfs publication cpufreq_policy_alloc() allocates policy->cpus with alloc_cpumask_var(), i.e. without __GFP_ZERO, unlike the sibling related_cpus and real_cpus masks. With CONFIG_CPUMASK_OFFSTACK=y the mask is a separate kmalloc_node() allocation, so its bitmap holds whatever the slab allocator left behind: cpufreq_online() cpufreq_policy_alloc() alloc_cpumask_var(&policy->cpus) /* bitmap is uninitialized */ kobject_init_and_add() /* policy%u/ appears in sysfs */ cpufreq_policy_online() cpumask_copy(policy->cpus, cpumask_of(cpu)) /* first valid value */ This leaves a window in which the sysfs attributes are already reachable while policy->cpus is still garbage. show()/store() gate on policy_is_inactive(), i.e. cpumask_empty(policy->cpus), so a non-zero bitmap makes them run the attribute callbacks on a policy that is not initialized yet. Fix this by using zalloc_cpumask_var() for policy->cpus.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

2fc3384dc75bf7333384c7a16d12c796f61c3f564.2
Vendor states this is fixed in 06f273d29e5e0fe5c775a65c563fbeed8cd94c7a (fixed)
Vendor states this is fixed in 0de2f3918fbbbb767e7e716178194b66560dd12a (fixed)
Vendor states this is fixed in 54d37bcf2f497140b9207968557ddb484058e749 (fixed)
Vendor states this is fixed in 6e166b9281dec98aed19213a84235250e5fdb081 (fixed)
Vendor states this is fixed in bbc0472d2270bf732142ca71579d6ede636174ed (fixed)
Vendor states this is fixed in ca52482508b3ac9febe74ca4f732647d394727b8 (fixed)
Vendor states this is fixed in e13370c5b549712f49f80234df249303381c53b4 (fixed)
Vendor states this is fixed in e807920031ca32b668f9e7a1efbd21858f03d64b (fixed)
Vendor states this is fixed in 4.2 (unaffected)
Vendor states this is fixed in 5.10.271 (unaffected)
Vendor states this is fixed in 5.15.222 (unaffected)
Vendor states this is fixed in 6.1.189 (unaffected)
Vendor states this is fixed in 6.12.111 (unaffected)
Vendor states this is fixed in 6.18.53 (unaffected)
Vendor states this is fixed in 6.6.158 (unaffected)
Vendor states this is fixed in 7.2.7 (unaffected)
Vendor states this is fixed in 7.3 (unaffected)
Vendor states this is fixed in 7.3-rc3 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

Quick Info

StatusRECEIVED

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Free plan, no card