CVE-2026-43401
NULL Pointer Dereference in Linux Kernel cpufreq Intel Pstate
Publication date: 2026-05-08
Last updated on: 2026-05-08
Assigner: kernel.org
Description
Description
CVSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| linux_kernel | linux_kernel | * |
| linux | linux_kernel | * |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability exists in the Linux kernel's intel_pstate driver, specifically in the update_cpu_qos_request() function. The function attempts to initialize a variable by dereferencing a pointer without first verifying if the pointer is valid. On systems booted with the "nosmt" parameter, some CPU data pointers are NULL for SMT sibling threads. As a result, when update_qos_requests() is called, it tries to access data through a NULL pointer, causing a NULL pointer dereference error.
The issue arises because the code accesses the 'freq' variable too early before confirming the validity of the policy and driver data. The fix involves deferring the assignment of 'freq' until after these validations, preventing the NULL pointer dereference.
How can this vulnerability impact me? :
This vulnerability can cause a NULL pointer dereference in the Linux kernel, which typically leads to a kernel crash or system instability. On affected systems, this could result in unexpected reboots or denial of service conditions, impacting system availability.
What immediate steps should I take to mitigate this vulnerability?
The vulnerability is fixed by deferring the 'freq' assignment until after the policy and driver_data have been validated in the intel_pstate driver within the Linux kernel.
To mitigate this vulnerability immediately, you should update your Linux kernel to a version that includes this fix.
Additionally, avoid booting systems with the 'nosmt' parameter until the fix is applied, as the issue occurs on systems booted with this parameter.