TCP Vulnerability in Linux Kernel Affecting Memory Management

CVE-2023-53669

What is CVE-2023-53669?

A vulnerability has been identified in the Linux kernel's TCP implementation that affects memory management during transmission. Specifically, the function skb_copy_ubufs() can lead to crashes when handling zerocopy TCP transmissions with hugepages, particularly if the skb length exceeds approximately 68 KB. This occurs due to an erroneous assumption within skb_copy_ubufs() regarding the ability to copy payloads using a limited number of MAX_SKB_FRAGS order-0 pages. With BIG TCP allowing skb sizes up to 512 KB, this oversight may result in instability for systems under specific network configurations. A resolution has been implemented, where higher order pages can be utilized when necessary to prevent memory leakage and enhance system reliability.

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