cve 2025 40057

CVE-2025-40057 is a Linux kernel vulnerability in the PTP (Precision Time Protocol) subsystem, addressed by bounding the max_vclocks parameter to prevent unsafe kcalloc allocations. The fix ensures user-controlled values cannot trigger overflow or excessively large memory requests. This tag covers discussion of the CVE, its discovery via syzbot fuzzing, and the kernel patch that adds an upper bound to max_vclocks. While the vulnerability is in the Linux kernel, it is relevant to Windows users running virtualized or WSL environments that rely on PTP for time synchronization. The tag provides information on the technical details of the bug and the mitigation applied.