CVE-2025-40239
Published Dec 4, 2025
Modified Apr 15, 2026
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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References
Frequently Asked Questions
What is CVE-2025-40239? +
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.
How do I check if I'm vulnerable to CVE-2025-40239? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.