CVE-2025-40147
BaseFortify
Publication date: 2025-11-12
Last updated on: 2026-03-25
Assigner: kernel.org
Description
Description
CVSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| 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 is a race condition in the Linux kernel's blk-throttle subsystem during throttle policy activation. Specifically, during repeated cold boots, a NULL pointer dereference can occur in the blk_should_throtl() function because the throttle policy is consulted before it is fully enabled for the queue. The check for q->td != NULL is insufficient during early initialization, allowing blkg_to_pd() to return NULL and causing a NULL pointer dereference later in the code. The fix involves tightening the blk_throtl_activated() check to ensure the throttle policy bit is set on the queue before accessing throttle group state, preventing premature access to uninitialized policy data.
How can this vulnerability impact me? :
This vulnerability can cause the Linux kernel to crash due to a NULL pointer dereference during system boot or early initialization. Such crashes can lead to system instability, denial of service, or unexpected reboots, potentially impacting system availability and reliability.
What immediate steps should I take to mitigate this vulnerability?
To mitigate this vulnerability, update the Linux kernel to a version that includes the fix for the blk-throttle access race during throttle policy activation. The fix ensures that blk_should_throtl() does not access throttle group state until the throttle policy bit is set on the queue, preventing NULL pointer dereferences during early initialization.