CVE-2024-41020: 
Linux Kernel vulnerability analysis and mitigation

CVE-2024-41020 is a vulnerability in the Linux kernel's filelock system, specifically affecting the fcntl/close race recovery compat path. The vulnerability was discovered on July 29, 2024, and affects the file locking mechanism in both the normal version and the version for 64-bit offsets on 32-bit kernels (NVD).

The vulnerability stems from a code duplication issue in the filelock system where there are two copies of the code handling lock recovery: one for normal operations and another for 64-bit offsets on 32-bit kernels. The issue was introduced in commit c293621bbf67 ('stale POSIX lock handling') and was fixed by modifying how the system handles fcntl/close race recovery in the compat path (Kernel Commit).

When a race condition occurs between fcntl and close operations, the system may not properly handle file locks, potentially leading to reliability issues in file locking mechanisms. This affects systems running the Linux kernel, particularly those using 32-bit architectures with 64-bit offset support (Ubuntu Security).

The issue has been fixed in various Linux kernel versions across different distributions. Ubuntu has released patches for multiple kernel versions including 6.8.0-48.48 for 24.04 LTS, 5.15.0-125.135 for 22.04 LTS, 5.4.0-200.220 for 20.04 LTS, and 4.15.0-233.245 for 18.04 LTS. The fix involves modifying how the system handles lock removal during fcntl/close race conditions (Ubuntu Security).