Userspace-Supplied XDP Descriptor Validation Flaw in Linux Kernel

CVE-2025-40159

What is CVE-2025-40159?

A vulnerability has been identified in the Linux kernel's handling of userspace-supplied XDP descriptors. This flaw can allow invalid values to pass the validation process, potentially leading to undefined behavior or the queuing of invalid frames for transmission. Specifically, situations can arise where an overly large descriptor length or a negative address due to integer overflow can bypass validation checks. Though legitimate applications using XSK are unlikely to encounter these issues, attackers may exploit this vulnerability to disrupt normal operations. The kernel has been updated to reinforce descriptor validation practices, preventing such overflows through the promotion of descriptor length checks and careful validation of addresses.

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