CVE-2025-40239
Unknown Unknown - Not Provided
BaseFortify

Publication date: 2025-12-04

Last updated on: 2025-12-04

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: net: phy: micrel: always set shared->phydev for LAN8814 Currently, during the LAN8814 PTP probe shared->phydev is only set if PTP clock gets actually set, otherwise the function will return before setting it. This is an issue as shared->phydev is unconditionally being used when IRQ is being handled, especially in lan8814_gpio_process_cap and since it was not set it will cause a NULL pointer exception and crash the kernel. So, simply always set shared->phydev to avoid the NULL pointer exception.
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Meta Information
Published
2025-12-04
Last Modified
2025-12-04
Generated
2026-06-16
AI Q&A
2025-12-04
EPSS Evaluated
2026-06-15
NVD
CVE-2025-40239
EUVD
EUVD-2025-201220
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
linux linux_kernel *
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Exploitability
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KEV
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CWE ID Description
CWE-UNKNOWN
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Executive Summary

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.

Impact Analysis

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.

Mitigation Strategies

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.

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