Linux Kernel Vulnerability Affecting espintcp and Async Crypto Functionality

CVE-2026-31518

What is CVE-2026-31518?

A memory leak vulnerability exists in the Linux kernel's espintcp module, which mishandles packet memory management when the transmission (TX) queue is full. Specifically, when the esp_output_tail_tcp function encounters an error, it fails to free the socket buffer (skb) due to improper synchronization in the crypto handling process. The error response mechanism does not adequately drop the skb when using asynchronous crypto operations, which can lead to memory being unnecessarily allocated and not released. This could potentially exhaust system resources or lead to degraded performance over time.

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