Usercopy Vulnerability in Linux Kernel Affecting Network Socket Handling

CVE-2026-22977

What is CVE-2026-22977?

A vulnerability exists in the Linux kernel related to improper handling of usercopy operations in socket error queues. Specifically, this flaw arises when sk_buff structures allocated from skbuff_fclone_cache are manipulated without a defined usercopy region, leading to potential kernel memory exposure during error handling. When a user attempts to read from the socket error queue, accessing certain fields can trigger a usercopy hardening violation, causing the kernel to crash. This issue is particularly pertinent when CONFIG_HARDENED_USERCOPY is enabled, emphasizing the need for immediate attention and mitigation strategies to safeguard against potential exploitation in network operations.

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