CVE-2024-40985: 
Linux Kernel vulnerability analysis and mitigation

CVE-2024-40985 is a vulnerability in the Linux kernel's TCP Authentication Option (TCP-AO) implementation that was discovered in July 2024. The issue involves a memory leak in the net/tcp_ao subsystem when handling error paths during TCP-AO configuration (Kernel Git).

The vulnerability was introduced alongside the TCP_AO_CMDF_AO_REQUIRED functionality in version 5 of the TCP-AO patches. Specifically, the issue occurs in the tcp_ao_info_cmd function where ao_info was not properly freed on the error path when tcp_ao_required_verify fails (Kernel Git). The bug was fixed by properly handling the error case and adding a goto statement to ensure proper cleanup (Red Hat).

The vulnerability has been assessed as having a Low severity impact. The issue could potentially lead to memory leaks in the kernel when configuring TCP Authentication Option settings (Red Hat).

The vulnerability requires local access and can only be triggered through specific TCP-AO configuration operations. There are no known exploits in the wild (Red Hat).

The issue has been fixed in multiple Linux kernel versions. Ubuntu has released patches for version 24.04 LTS (linux 6.8.0-44.44), and various other kernel variants including linux-aws, linux-azure, and linux-gcp have also been updated (Ubuntu). Users are advised to update their kernel to the patched versions.