CVE-2023-52778: 
Linux Kernel vulnerability analysis and mitigation

CVE-2023-52778 affects the MPTCP (Multipath TCP) implementation in the Linux kernel. The vulnerability was discovered when TCP sockets and MPTCP subflows could build egress packets larger than 64K, which exceeds the maximum DSS (Data Sequence Signal) data size. This issue was identified on November 14, 2023, and affects systems using MPTCP networking capabilities (Kernel Commit).

The vulnerability stems from a previous commit (7c4e983c4f3c) that allowed gso_max_size to exceed 65536 bytes. When packets exceed the maximum DSS data size, the length is misrepresented on the wire, leading to stream corruption. The issue manifests in the MPTCP protocol implementation, specifically in the net/mptcp/protocol.c file, where packet sizes were not properly bounded to MPTCP's limitations (Kernel Commit).

When exploited, this vulnerability can cause stream corruption and trigger kernel warnings. The issue affects the data integrity of MPTCP connections and can lead to system warnings such as 'WARNING: CPU: 0 PID: 9696 at net/mptcp/protocol.c:705' (Kernel Commit).

The vulnerability can be triggered when using MPTCP connections with large packet sizes. It requires access to a system using MPTCP networking capabilities and the ability to manipulate packet sizes (Kernel Commit).

The issue has been fixed by explicitly bounding the maximum GSO size to what MPTCP actually allows. The fix introduces a MPTCP_MAX_GSO_SIZE definition and adds checks to ensure the sk_gso_max_size does not exceed this limit (Kernel Commit).