Memory Management Vulnerability in Linux Kernel Affecting skb Heads

CVE-2026-31429

What is CVE-2026-31429?

In the Linux kernel, a notable vulnerability related to memory management has been identified within the skb (socket buffer) heads concerning allocation and deallocation. The flaw arises when KFENCE is activated, leading to misclassification during the free path of allocated memory objects. Specifically, the mismatch occurs when the size of allocated skb head data inadvertently aligns with the SKB_SMALL_HEAD_CACHE_SIZE. This condition disrupts the intended allocation route, resulting in an erroneous cross-cache free operation, which can compromise the stability and security of the kernel's memory handling processes. A fix has been implemented to ensure that all skb head frees revert to a generic path, mitigating the risks associated with the incorrect slab cache type.

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