CVE-2025-40239
BaseFortify
Publication date: 2025-12-04
Last updated on: 2025-12-04
Assigner: kernel.org
Description
Description
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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 occurs in the Linux kernel's handling of the LAN8814 PHY device. During the LAN8814 PTP probe, a shared pointer (shared->phydev) is only set if the PTP clock is actually set. If the PTP clock is not set, the function returns early without setting shared->phydev. However, shared->phydev is used unconditionally later, especially during IRQ handling in the lan8814_gpio_process_cap function. Because shared->phydev may be NULL, this leads to a NULL pointer exception and causes the kernel to crash. The fix is to always set shared->phydev to avoid this NULL pointer dereference.
How can this vulnerability impact me? :
This vulnerability can cause the Linux kernel to crash due to a NULL pointer exception when handling interrupts related to the LAN8814 PHY device. Such kernel crashes can lead to system instability, downtime, and potential loss of data or service availability.
What immediate steps should I take to mitigate this vulnerability?
Update the Linux kernel to a version where the LAN8814 PHY driver always sets shared->phydev during the PTP probe, ensuring that the NULL pointer exception is avoided and the kernel does not crash.