The Linux kernel's D-Link network driver did not properly handle the failure of the netdev_alloc_skb_ip_align() function, which allocates socket buffers (skb). If this allocation failed, subsequent dereferencing of skb->protocol would cause a NULL pointer dereference, leading to a denial of service via kernel crash. The patch introduces a fallback mechanism to handle allocation failure gracefully, preventing the NULL pointer dereference. This vulnerability is tracked as CVE-2025-40053 and has a CVSS 3.1 base score vector indicating network attack vector, low attack complexity, no privileges required, no user interaction, unchanged scope, no confidentiality or integrity impact, but high availability impact.

Successful exploitation results in a NULL pointer dereference in the kernel, causing a denial of service by crashing the affected system. There is no impact on confidentiality or integrity. The vulnerability affects availability due to potential kernel panic or system crash.

A patch has been applied to the Linux kernel to handle the allocation failure properly by falling back to a normal path if skb allocation fails. Users should update to the fixed kernel version once available. Patch status is not explicitly confirmed in the provided data; therefore, check the official Linux kernel advisories for the exact fixed versions and apply updates accordingly.